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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

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Old 6th Oct 2011, 2:04 pm   #1
Darren-UK
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Default Reviving your old record player.

Introduction

To skip this introduction scroll to the Index in post #2.

At the time of writing we are seeing an upsurge of interest in vintage record players and this guide is intended to accompany other related guides which are 'Stickies' in our Vintage Audio section. This guide is concerned only with vintage (by the forums definition of the term) postwar domestic record players operated either by mains electricity, batteries or mains/battery power. Excluded, therefore, are acoustic (ie wind-up) gramophones, professional DJ equipment, radiogramophone amplifiers, car record players and oddities such as the Discatron and Discassette. Non radiogram stereophonic machines are also largely excluded due to their varying degress of complexity. There is, however, some general information due, in part, to the existence of 'stereo capable' machines which make use of an external, add-on, amplifier unit.

Sometimes a record player might be known to be in good electrical order, but apparently isn't functioning correctly mechanically. Occasionally it transpires the 'problem' is nothing more than the owner not knowing how to operate the machine correctly. If this applies to you, you will find a guide to operating autochanger machines, also in the section linked to above. If you intend/need to do electrical work, and you most probably will, then you'll need service data. Data for many record players can be obtained from VRSD.

This guide contains links to other threads in our forums, as well as to pages in our main website. This has been done to avoid too much duplication in this guide, although some duplication has been unavoidable. However, if you're a complete beginner remember that you can print out much of the information and/or save pages to your PC. This provides the benefit of having information in front of you when you start work on your record player; much better than shuttling back and forth between your PC and your workbench, kitchen table, shed or whatever.


General scenarios and information


The commonest scenarios are of somebody obtaining a record player which has either been:
  • Stored away for years in a shed, cellar, loft etc. by the person who now wishes to start using it again.
  • Obtained on a whim from a car boot sale, antiques centre or wherever and, consequently, with a totally unknown history.
  • Obtained with the reassuring guarantee from the vendor that it was "plugged in, went round and made a noise" but without realising that the "noise" could, in fact, have been a loud bang.

All of the above are scenarios which our forums cover around 16 times per week, 33 times per fortnight, about 45 times every three weeks and around 78 times per month. Most faults and remedies can be found by the simple expedient of doing a forum search. However, we appreciate that this is all well and good if you already have some knowledge of how record players work, as well as some knowledge of the relevant electronics and mechanics.

So to summarise the above, this guide is aimed at the newcomer who just wants his/her record player to operate safely and reliably but who may only have little, or no, relevant technical knowledge.

Furthermore, it isn't practical to herein and hereinafter teach you everything about electronics beyond, say, component recognition and replacement. Nor is it practical to detail very make/model or record player or deck, to do so would require the writing of a quite hefty book. It is therefore recommended that you read up, within these forums and the parent website, about capacitors (including smoothing and reservoir 'cans', as they tend to be called), resistors, transformers (mains and output), the differences (apart from the obvious) between valved and transistorised amplifiers, power supplies and in particular the differences between machines designed for AC only power and those designed for AC/DC power.

Remember that all mains powered equipment, especially if old, is potentially dangerous. This applies even more so to the aforementioned machines designed for AC/DC power.

Perhaps needless to say, not every newly acquired record player needs much work doing to the electronics side. Sometimes none at all needs doing (loosely, 1970's onwards equipment) but, in all cases it's extremely unwise to omit some basic safety checks. Most problems with the resurrection of old and long-disused record players centre around the deck mechanics and the cartridge and stylus (singular), styli (plural). It is not "needle", unless you're in America, nor is the plural "stylii".

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^ Whilst on the subject of terminology, the image above shows the usual names for the various deck components and which will be used throughout this guide. Please, too, try and refrain from using the word "turntable" unless you're specifically talking about what is sometimes known as the "platter". Saying "turntable" when you in fact mean the "deck" causes confusion for the uninitiated. Although the deck shown above is typical, be aware that the design and on-deck position of certain components can - and do - vary. Overarms vary and some, for example, are mounted on the opposite side of the deck. Record size detectors too; that shown operates vertically, others operate horizontally albeit triggered by the vertical dropping of a record. Certain Collaro decks, see a later post, operate entirely differently.

Staying with terminology, it's worth mentioning another problem which is common in the forums and could mean the difference between a lot of agro or quick success. This concerns make/model of record player married to make/model of deck. We often have members posting something like "Hi, I have a Bush Monarch record player" or "Hi, I have a Dansette Garrard....blah blah". These words are meaningless and you may as well go on a car forum and say "Hi, I'm having trouble with my Vauxhall Petrol" or ".....my Ford four door". Bush, Dansette and so forth are record player brands, Monarch is a BSR deck of which several versions existed. Garrard is also a deck of which there were numerous different models.

So if you find the need to post a question in the forums, make sure you quote the make and model of your record player as well as the make and model of its deck. Correct would be "Dansette Conquest with Garrard Autoslim deck" or "Bush SRP31D with BSR Monarch UA15 deck" and so forth.

To get down to business, we'll begin with the safety checks and then move on to the main components of a typical mains powered, mono, record player fitted with an autochanger deck; these being the power supply, amplifer and the deck itself.

However, if you know (and that's know as opposed to assume) your record player is electrically safe and thus can be shown 230 of those volt thingies but has some other problem, then you can go to the relevant page, or link, via the Index below.
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Old 6th Oct 2011, 2:04 pm   #2
Darren-UK
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Default Index.

Page numbers given below may refer to the entire page, or pages, or items within a page which will be highlighted in bold text.
  • A
    AD161/2, AF11x series (Transistors) 14.
    Add-on decks 15.
    Add-on amplifer/speaker units
    Amplifiers 10.
    Autochanger decks 4-9.
  • B
    Batteries (AD28, D and PP9) 13.
    Battery operated record players 13.
    Bearings (Ball races) 7.
    Bearings (Sintered) 7.
    Belt+idler drive (older Garrard decks) 6.
    Biasing 14
    BSR 4-9, 11.
    Bush SRP series 14.
  • C
    Cabinet fittings 20.
    Cartridge suppliers 11.
    Cartridges (Crystal [Rochelle] and Ceramic) 11.
    Cartridges and styli, the difference between 11.
    Cheney 20.
    Collaro 4, 9.
    Collaro Conquest and Studio 9.
    Control knobs 20.
  • D
    Dampness 3.
    DC Can Motor 13.
    Deck, common faults list 5.
    Deck component terminology 1.
    Deck mechanics 7.
    Disc Jockey (Philips) 16, 17.
    Double C (HMV/EMI) 18.
    Dropper resistor 10.
  • E
    E Series valves 10.
  • F
    Fuse (mains plug) 3.
    Fuse (internal) 3.
  • G
    Garrard 4
    Governor (Speed) 13.
    Grommets 4
  • H
    Heatsink 14, 19.
    High tension 10.
    His Master's Voice (HMV/EMI) 18.
    Hum 10.
  • I
    Idler (wheel) drive 6.
  • J
  • K
  • L
    Lamp Limiter 3.
    Low tension 10.
    Lubrication (Deck) 7.
  • M
    Mains plug and lead, how to wire 3.
    Mains/battery record players 13.
    Milliammeter 14.
    Motor (Mains, Shaded Pole) 8.
    Multiple loudspeaker machines (non stereo) 19.
  • N
  • O
    Ovearm 1 (image).
  • P
    Philips (Cartridges) 11.
    Philips non-auto record players 16.
    Philips autochanger record players 17.
    Powering up 3.
    Power supply (Mains) 10.
    Push-Pull (amplifier) 10.
  • Q
  • R
    RCD 3.
    Resistors 10.
  • S
    Safety checks 3.
    Selenium rectifer 10.
    Service data (also here) 10.
    Smoothing capacitor 10.
    Stereophonic (General information only) 19.
    Strobe disc 8.
    Stylus/Styli 11.
    Stylus/styli and cartridges, the difference between 11.
    Stylus/styli suppliers 11.
  • T
    Tonearm 1 (image).
    Tracking weight 12.
    Transformer (Auto) 10.
    Transformer (Mains isolating) 10.
    Transformer (Output) 10.
    Transistorised record players 14.
    Trip Pawl (BSR/Garrard) 4.
    Trip Pawl (Collaro) 9.
    Turntable mats 20.
    Turntable speed 8.
  • U
    U Series valves 10.
  • V
    Valves (Rectifier) 10.
    Valves (Signal) 10.
    Valve bases 10.
    Valve faults (list) 10.
    Visual (safety) checks 3.
  • W
    Warning (Safety) 1.
  • X
    X type cartridges (BSR X3, X5) 11.
  • Y
  • Z
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Old 7th Oct 2011, 11:35 am   #3
Darren-UK
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Default Is it safe to plug in?

Safety checks and powering up

We're all tempted to do it; obtain an old record player, radio or whatever and plug it in to see if it works whilst keeping our fingers crossed that all will be well. Temptation is one thing, doing it is another. Don't do it. Follow the basic checks as outlined below before plugging in.

Dampness


Any mains powered electrical equipment which has been exposed to damp must be thoroughly dried out before you apply power. This especially applies to equipment with an unknown history. For example, the old record player you found sitting on the grass at the car boot sale or the one you bought from an advertisement which stated "Found while clearing out grandad's garden shed".
Dampness will also kill a record player cartridge, crystal types in particular but more on that later.


Mains plug and lead


Mains leads, indeed any cable of the 'flex' type, consists of two or three cores which themselves comprise a number of fine wire strands. 'Flex' is an abbreviation for 'Flexible cable', as needed for domestic applicances of all types. For the purposes of this post we'll use the terms 'flex', 'core(s)' and 'strands'.

First of all, see what mains plug, if any, is fitted. If it's an old round-pin type this should tell you something, ie that the machine very probably hasn't seen the mains for decades. Such a plug is most likely to be unfused too. Even if a more modern 13A plug is fitted, don't be complacent. It might mean the machine has been used in recent times, but then again it's no guarantee of safety. Remember that 13A plugs have been around since the 1940's.

So if no, or a round pin, plug is fitted, obtain a good 13A plug and fit a 3A (Max) fuse. If a 13A plug is already fitted then open it up, check the fuse rating and replace if necessary. Then check the Live and Neutral cores terminate correctly and are secure. New 13A plugs are usually sold with a 13A fuse fitted. Unfortunately many people think this 13A fuse is fine to use with any applicance, not so. Please read on for more detailed information.

Now turn to the mains flex. Check it thoroughly along its length for splits, scuffs or any other damage. Pay attention, too, to the point where the flex enters the record player cabinet. Sometimes it passes through a little notch cut into the cabinet lid and damage can occur there. Remember that mains flexes, being external to the record player, are very prone to damage - damage that may not be evident at a glance.

Is the mains flex the now-obsolete single insulated type? If it is, you may care to replace it with modern double insulated type. Bear in mind the plug fuse is there to protect the flex, so ideally the flex should be of a higher rating than the plug fuse. For example, with a 3A fuse fitted the flex should be of higher rating, which will be 6A. Should a 6A flex not fit through the cabinet's cable entry, then you can fit 3A flex but with a 2A fuse in the mains plug. Plug fuses of below 3A rating are not commonly available on the High Street but can be obtained online. "Plug fuse", by the way, is the usual name for, well, a plug fuse. Don't just ask for 'a fuse' as there's numerous different types.

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^ From time to time people can be confused by mains wiring colours, cable/lead/flex types and even how to wire a mains plug correctly. To assist, a few images of plugs and flexes are included. The double image above shows, at left, a plug fitted with an obsolete two-core, single insulated flex. These flexes consist of nothing more than two cores siamesed together. Despite the impression the image may give, the insulation of the cores and thus the whole flex is invariably of one colour.

There is an safety important issue concerning obsolete flex which is omni-coloured and this centres upon polarity. Indeed, it could apply to any type of flex. Normally the live side of the mains will connect to the input side of the mains switch (that's the record player's on/off switch). This means that when connected to the mains but the record player itself is switched off, the amplifier will be electrically isolated ('dead' if you like). However, sometimes either through error or, to cover any possible eventuality however unlikely it may be, through design, the on/off switch may be connected in the neutral side of the mains supply. This means, of course, that with the mains connected and the on/off switch off, the amplifier will be live. This obviously brings into question the power supply to the motor but this paragraph is adequate enough to warn of possible mains polarity problems. As will be repeated many times within this guide, if you've any uncertainties then please take no risks and ask in the forums.

Staying with the lefthand view above, we move to the plug itself. Note the 'V' shaped cable gripper; this type is designed to tighten its grip if the flex is for some reason pulled or placed under tension. Less common these days they are, however, very suitable for flat cross section mains flexes. Round section flex, especially if above 3A rating, can be difficult to insert. Note, too, the means of securing the cores of the flex. These consist of a knurled and slotted nut (screw on with fingers, tighten with screwdriver) with an integral washer. There is normally also one (often) or two (ought to be) other washers present, between or beneath which the cores are inserted before the nut is screwed on and tightened. The nuts and their studs have conventional righthand threads, therefore the bare strands of the cores should be twisted together and then looped around the threaded stud in a clockwise direction. Do not do it anticlockwise or the core will be forced out as you tighten the nut. Before refitting the plug lid, ensure no stray strands of wire are present which could project outside the assembled plug. This, of course, applies to any plug.

Moving now to the righthand view, we can see a more modern (but nonetheless now also obsolete in respect of wiring colours) flex fitted to a different type of plug. The flex depicted is still two-core but this time is double insulated; each core is insulated and they in turn are protected by a common outer insulating sleeve. Wiring (core) colours are now red (live) and black (neutral). Note the different and more familiar type of clamp, using a pair of screws for securing. The method of securing the cores to their respective plug pins is also the more familiar male screw type. These should be tightened so the cores are secure in the pins but with some slack between the pins and the clamp. Do not overtighten the screws as they can chew right through the wire strands and force you to start all over again.

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^ This image is similar to that described in the immediately preceding paragraph. The difference being that the flex is now a three-core type with, of course, earth.

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^ This image shows a modern two-core flex using the current, at the time of writing, wiring colours; brown (live) and blue (neutral).

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^ This is the same as the previous image except that this time the flex is three-core and has the current green/yellow earth. Compare this to the earlier three-core arrangement.

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^ This image shows something of an oddity which, nevertheless, you may well come across as it isn't exactly uncommon. Pay attention to the fact that the black core is live and the white core is neutral in this and only this case. Note the plug, in this instance the word 'green' is present in full to denote the earth connection.

On wiring mains plugs in general, if an earth core is present then this should be given more slack between pin and clamp than the live and neutral cores. This is to ensure that in the event of the flex being tugged to the point where it exits the plug, the earth will be the last connection to remain in situ.

One final point before we move on. Not many portable record players were earthed from new. In some cases this was for cheapness (ie the machine could've been earthed but it wasn't deemed essential) and in others it was for technical reasons, in particular AC/DC machines.* Therefore DO NOT attempt to earth any part of a record player without first seeking advice but, in a nutshell, if it wasn't earthed from new then do not attempt to earth it now. Some people think earthing the record deck is a good idea in an attempt to reduce hum. However, the danger is a fault (even in the wiring at or to your 13A sockets) causing the deck to become live. For that reason, even many decades ago some domestic appliances came with the warning "This appliance must not be earthed". The Hoover Constellation vacuum cleaner was one example which comes instantly to mind.

* For general interest, other reasons for non-earthing once existed. At one time in the dim and distant past not everybody had mains electricity in their homes. Of those that did, it might initially have been confined to lighting or lighting plus an absolute bare minimum of wall sockets. For this reason many appliances were connected via lighting bayonets and yes - this meant cables going up from a table or whatever to the ceiling. Special, sometimes switched, lighting bayonet sockets could be obtained for this purpose. None of these ceiling bayonets were earthed, being Bakelite or even wood, so earthing of appliances was at that time seen as pointless. When, in time, wall sockets became common, not all were three-pin; some were two-pin and hence still no earth.

In some areas DC mains existed. Often this was because power came from an existing, probably corporation owned, local power station built to supply trams and trolleybuses with DC power. This is the main, but not the only, reason why some radios and record players were built to be capable of running from AC or DC power (or in a few rare cases, DC power only) and thus were not earthed.


Basic short - and open - circuit checks


Now go grab your multimeter. The record player must be disconnected from the mains during the following checks.

Set your meter to a resistance range, ensure the on/off switch on the record player is off and connect the meter across the L/N pins of the mains plug. There should be no reading (ie zero if using a digital meter, infinity if using an analogue meter), if there is there's a short circuit somewhere between the mains plug and, or at, the on/off switch. If all is well, do the same again but with the record player switched on. There should now be a meter reading (meter needs to be set on a higher Ohms range for this) of a few hundred to a couple of thousand Ohms; the exact reading being dependant upon a number of factors. Don't worry if this reading begins to vary a little after a few seconds.

At this stage it's a wise idea to do a quick check on the electrical condition of the smoothing/reservoir capacitor (see post #10). Take the capacitor out of circuit (ie disconnect electrically) and switch your meter to its highest Ohms range. Connect the meter across the tags and watch the reading; you should get a low reading initially, climbing to a much higher reading. Now withdraw the meter probes and discharge the capacitor (meters on resistance ranges will charge the capacitor). Discharge by simply shunting a high value resistor across the tags or, if you don't have one, short the tags with a screwdriver and wait a couple of minutes. Note; DO NOT discharge a capacitor in this makeshift manner if the capacitor has been charged from the mains.

Having done this, grab your meter again and repeat the test. If you obtain the same, or very nearly the same, reading as you did first time around then the capacitor can be deemed serviceable.

Moving on, now connect one meter probe to an unpainted metal part of the deck, the stacking spindle is probably the most convenient. Connect the other probe to the L and N mains plug pins in turn; no reading should be obtained.

Few vintage record players were earthed as-built, although some may have had their decks earthed by a previous owner. If the mains plug has an earth connection, switch the record player on and check with your meter between the earth and live pins, then the earth and neutral pins. No reading should be obtained. Next connect your meter between a metal part of the deck and the earth pin of the mains plug (the record player may be on or off for this check). If the deck is earthed, the meter will show continuity. If this is not the case, then you'd be wise to find out where the earth is connected to. You're advised to create a forum thread in such an instance, giving as many details as possible, as your record player may have undergone a post-manufacture modification (perhaps in an attempt to reduce hum) which may or may not be safe.

Internal visual checks


You should now remove the deck complete with its wooden plinth. Usually this is located by four visible screws with cup washers, but sometimes access is by removal of the front grille. Before lifting, ensure the tonearm is secure on its resting post and remember that the deck can only be lifted to the extent the wiring allows. You will now have access to the power supply and amplifier.

First of all, look for any disconnected and/or damaged wiring. Next have a look at the smoothing can; this is a large electrolytic capacitor in an aluminium can (actually two or maybe three capacitors in the one can). Have a look at the end of the can where the terminals are located; is it bulging? is there a mould-like, or goo, substance oozing out anywhere? If any of these fault indications are present then replace the component and DO NOT apply power until you've done so. If faulty, this component can explode with some force.

If all appears visually OK so far, take a look at the other components. Is a mains transformer present (AC-only machines)? If there is, check for little piles of wax beneath or on the transformer. If present, other than in very minute quantities, there's likely a fault. If no mains transformer then there'll be a dropper resistor (AC/DC machines). Are all connections intact and set for the correct voltage? Is the resistor itself intact? On the subject of correct voltage, sometimes a voltage selector with a moveable plug is present; if there is then check it's set correctly and that the plug is secure.

All good so far? Right, now have a look at the other components. Look for broken and/or heavily burnt resistors. These are generally cylindrical components with coloured bands around them. Look for other capacitors; these take many forms but look in particular for any which are a yellowish colour and covered in a sticky, waxy, mess. If any are present then replace them. Other capacitors may have brown or black moulded cases; these may be ok, but by inference some may not be. Record players contain, in the main, very few components compared to a radio anyway.

Next, if this is a valved machine take a look at the valve(s). Is this glass intact? is the glass a milky colour? (if it is, the valve has had it), are the valves securely seated and, if more than one, in their correct sockets? If unsure of this, service data will tell you and there may also be a little label inside the cabinet telling you the valve(s) and correct position(s). It's wise, too, to remove the valve(s) and check the pins are clean and undamaged while you're there.

If all appears well, it's now time to get out your can of Servisol Super 10 switch cleaner. You know, the one you bought in anticipation of acquiring a record player. Switch cleaning is not, obviously, a safety check, but as you've just been doing an inspection inside the machine it's convenient to do this now before you replace the deck.

Attach the little tube to the can and simply spray into any convenient gap, hole or whatever in the switches. Next, operate the controls several times through their fullest extent. Take care not to let spray/fluid got onto or into anything other than the controls.

At this point it would appear convenient to mention internal fuses. Usually one, occasionally two, are sometimes found on the chassis/PCB of better quality machines. Some manufacturers, Pye for example, used a fuse contained inside a polarised plug. These fuses are glass encapsulated types and must be replaced according to current rating (usually quoted in milliamps - mA). Voltage is irrelevant. If you find a blown fuse, look at the glass; if clean the fuse has probably just died from old age. If the glass is blackened, however, this would indicate a serious fault somewhere, ie a short circuit. If a blackened fuse is what you're faced with then DO NOT simply replace the fuse and attempt to power up again. If unsure then ask in the forum, giving details of your particular machine.

The Lamp Limiter


So all seems well, you've replaced the deck and set the 'transit screws' so the deck is nice and bouncy and you're ready to plug in and, hopefully, listen to that Des O'Connor LP you found in a cupboard the other day. Hang on though, you've done some visual checks and some cold checks with your meter but you still can't guarantee the machine is ready to see full power because you don't know, for example, if you've missed a short circuit anywhere and/or if the electrolytic capacitors are fit for purpose.

So to power up your old, but unknown, record player, you ideally need a reduced power supply and a means by which any problems will be indicated to you. What is known as a 'lamp limiter' conveniently serves both purposes and a crude one can be made up with readily available items.

This device is, quite simply, a domestic 60W or 100W filament lightbulb in series with the mains supply to the record player, radio or whatever. Our main website has a very good section on lamp limiters, from which you can gain information on making one, how to use it and its benefits.

Lamp limiters have infinite value to those who undertake repairs and restorations with any regularity but, of course, have little practical value otherwise. Many people who arrive at the forums with an old record player just wish to get that item - and the item only - working, so construction of a lamp limiter as per the article linked to above might seem something of an overkill. If this is you, then you can make a simpler lamp limiter for one-off use. Grab an extension lead (aka "Trailing Socket") with a switched socket, bulb holder and a removable, ie non moulded, mains plug. Remove the plug, cut off about 3" of the lead and pull out the live core. Discard the rest of the offcut. Next slit an inch or so of the lead's outer insulation from the now plugless end and pull out the live core. Take care NOT to damage any core insulation. Connect the live core to one terminal of the bulb holder and to the other terminal connect the piece of live core retained a few moments ago. Refit the mains plug; live core from bulb holder to live plug terminal and neutral + earth connections from the extension lead to their respective plug terminals. Fit a 60W or 100W filament bulb and away we go.

At this point it's worth mentioning that when using a lamp limiter with a record player, the latter's motor may not start - or may start but have insufficent torque to drive the turntable when the mechanism is engaged. For electrolytic capacitor reforming purposes, some people prefer to start with a 40W bulb, then progress to a 60W and then a 100W (if you do this, remember bulbs will be hot so use a glove or a dry cloth). The record player motor probably won't start via a 40W bulb but should when a 60W bulb is inserted.

With your makeshift lamp limiter as described you will not, obviously, be able to eventually switch the bulb out of circuit. You'll have to remove the lamp limiter and then connect the record player directly to the mains socket when you're satisfied it's OK to do so. When using the lamp limiter, ensure that you have easy and quick access to the switched socket of the extension lead in case you need to disconnect power instantly and without having to cross the room to reach the wall socket.

Once done and if you doubt you'll need the lamp limiter again, just remove the mains plug, chop off the end of the lead from which you'd earlier pulled out the live core for connecting to the bulb holder and refit the plug. You now have a normal extension lead once again.

Stepping back now, once the record player has been running with no problems via the lamp limiter for, say, twenty minutes, it's a pretty sound bet that all is well for applying full power. Remember that with the lamp limiter in-circuit, your machine is on reduced power so full performance will not be possible.

Finally, initially, at least, you may be wise plugging in via an RCD as well as a lamp limiter. An RCD is a Residual Current Device, like what you'd use to plug in your power tools, electric lawnmower etc via.

Thanks go to Graham (Station X) for the images in this post.
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Old 7th Oct 2011, 11:35 am   #4
Darren-UK
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Default The deck in general.

As this post's title implies, we're just having a look at a typical deck here but concentrating upon the most common cause of autochanger malfunctions; namely the Trip Pawl and its associated gubbins. This post is intended to accompany and expand upon this thread. Faults and lubrication issues are covered therein and also in other posts below. It's hoped the following images and text will give a clearer idea of how these parts of the decks function.

The deck used for the images is a BSR UA15. The arrangement seen is fairly typical although some older decks differ; some Garrard offerings, for example, had the cam below deck. Collaro had to be different too and their decks are touched upon in a later post.

The first two images below show the deck with the turntable removed. The third shows the bearing bush beneath the turntable. The fourth image, courtesy of forum member Howard, shows the adjustment points beneath a UA15 tonearm (See points 4, 5 and 6 in the next post). The fifth image, courtesy of Mike Phelan, shows what's below the turntable of a Garrard 3500 for comparison with the same view of a BSR UA15. For reasons of software constraints, below-deck views are included with later posts.

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^ On the left we can see a general view below the UA15 turntable. At left we can see the idler wheel, the stepped pulley (attached to motor shaft) and the three mounting points for the motor, with their rubber grommets. Failure of these grommets is often the cause of the turntable rotating at a speed other than the selected speed; this causes the motor to drop and thus the wrong section of the pulley to engage with the idler wheel.

At right we can see the stacking spindle, the cam and the essentials of the Trip Pawl (the brassy bit); this must be free to wiggle about - no grease - or the tonearm will lift off the record far too early. On the cam (the large diecast wheel) note the gap in the teeth adjacent to the spindle. The 'warped O shaped' part of the casting is the actual cam; below the deck is a cam follower which is linked, putting it simply, to the tonearm and this is what operates the auto cycle.

Note, too, the central bearing of the cam - which is secured in place with a circlip. Seizure of this bearing is often partly, but sometimes solely, responsible for the slowing or stopping of the mechanism during the auto cycle. In these circumstances you need to remove the cam, thoroughly clean and degrease the cam bearing and the spindle. This is often easier said than done; heat from a soldering iron being needed to free the cam in the worst cases. On some decks the spindle is of steel and seizure, after a long period of disuse, can occur due to a corrosive reaction between the diecast cam and the steel spindle. Compare the layout to that shown in Part 2 below.

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^
In this image we can see the pinion and projecting lug on the bearing beneath the turntable. The motor drives the turntable via the idler wheel and the pinion, in turn, engages the teeth around the cam to activate the auto cycle. How does it work? during play, the gap in the cam teeth sits opposite the spindle and clear of the pinion teeth. As the tonearm moves across the record during play, the trip pawl is 'brushed aside'. When the tonearm reaches the run-out groove at the end of a record it moves faster, this causes the trip pawl to 'lock', the cam is then turned so its teeth engage with the pinion and the auto cycle begins. From this simple description it will be understood why it's essential for the trip pawl to be free to wiggle about.

Of course, prior to playing some records the tonearm is sitting minding its own business on its rest. Therefore the auto cycle has be activated by some other means; hence the controls have an "Auto" (sometimes "Reject") position as well as a "Start" or "Manual" position. If the "Auto" control, which self- returns by spring tension, feels abnormally stiff and fails to activate the cycle, you should thus again examine the trip pawl mechanism and/or the linkage thereto.

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^ Above we see the underside of a standard BSR UA15 tonearm, showing the adjustment points. Refer to the relevant faults listed in Part 1 below if necessary. Beneath the body of the tonearm can be seen the long coil spring and the method, in this case, of anchoring. This is used to adjust and set the stylus tracking weight as recommended by manufacturers of styli and cartridges.

At bottom left can be seen a horizontal screw. This adjusts the horizontal tonearm positioning; ie the position relevant to the tonearm rest and the dropdown point on a record.

The large brassy-looking plate beneath and towards the rear of the tonearm adjusts the tonearm height; set too high and the tonearm won't lower onto a record and will strike records remaining on the stacker. Too low and the tonearm may be unable to lift clear of its rest and may strike the edge of a record on the turntable, or even strike the turntable itself.

The plate is adjusted by the screw just visible behind it, the head of which is accessible from the top of the tonearm. Also visible is the hollow brass nut, which is part of the tonearm pivot. During the auto cycle, a rod operates through this nut and acts upon the aforementioned plate to raise and lower the tonearm.

The arrangements are quite typical of many decks by several manufacturers BUT there are variations. Therefore if you have a deck which does indeed differ then conduct a forum search for your make/model or, if need be, begin a new thread on the subject (Registered members only).

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^
To round off this post, above we have a view of what lies beneath the turntable of a Garrard 3500 deck (Image courtesy of Mike Phelan). Note the clear similarities with the BSR deck depicted previously. Although the majority of old record players found today will have a similar arrangement, this is far from the case on every occasion. See Part 2 below and also the post concerning Collaro decks which, like some earlier Garrard decks, may have the cam mounted below the deck.
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Old 7th Oct 2011, 11:35 am   #5
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Default The deck, specifics Part 1.

This, obviously, is where the actual playing of records take place. Decks can be from a number of manufacturers, BSR, Garrard, Collaro and Philips (unfortunately in the case of Philips) being the commonest.

The deck consists of the turntable, tonearm, overarm, record size detector (the latter not in the case of certain Collaro decks) and relevant controls. Below the turntable and below the deck itself are the mechanics through which the deck functions operate, these mechanics being the usual cause of a deck failing to function properly in the mechanical sense. More on this later.

The tonearm (aka pickup) contains the cartridge, upon which the stylus (or styli, in plural form) is mounted. Please note that the plural of "stylus" is "styli" and not "stylii". Nor is the stylus a "needle", needles being what acoustic gramophones use. The term "needle" is, however, commonly used by DJ's and in the USA.

Cartridges, especially crystal types, will often have failed due to age and years of disuse. More on this in the following post.

Idler drives and deck lubrication are covered in detail in following posts, so in this post we'll list common deck faults and their possible causes (with causes in italics) as nine times out of ten these are the concerns surrounding newly acquired vintage record players:

1. Turntable speed erratic and/or insufficient torque.
Idler wheel problem, gummy motor bearings, gummy turntable bearing.

2. Turntable not rotating at a speed which corresponds with speed-change control setting.
Motor mounting points perished, or loose, causing motor and thus the stepped pulley to drop.

3. Mechanism slows significantly, or stops, during auto cycle.
Dried up grease and gummy oil on deck mechanics. Slipping idler wheel. Motor retarded due to gummy bearings.

4.
Tonearm lifts but fails to clear its rest, or strikes side of record or turntable, or strikes records on stacker during auto cycle.
Tonearm height adjustment, located at rear of tonearm, incorrectly set.

5. Tonearm does not settle fully onto its rest or does not lower properly onto record.
Same cause as 4. above.

6.
Tonearm returns to its rest but stops short of it, also will not lift off record at end of play.
Tonearm horizontal adjustment incorrectly set.

7. You wish to play a 7" record but tonearm drops for a larger record.
Record size detector jammed at a non 7" record setting.

8. Tonearm lifts off record too early, even though the adjustments in 6. above are correct.
Trip Pawl seized or sticking due to gummy oil or dried up grease (which should not be there anyway).

9. Tonearm skids across record.
Tonearm tracking weight set too low, stylus tip missing, stylus tip broken, stylus tip seriously worn, dirt and dust build-up around stylus tip, seriously worn and/or dirty record track, cartridge wires hanging down and fouling record, record player or deck not sitting approximately level.

10.
Tonearm encounters horizontal resistance with auto mechanism disengaged, causing it to jump the record track. Partially seized, or damaged, tonearm pivot and/or damaged below-deck mechanism. Note that with the auto mechanism disengaged, the tonearm should encounter no resistance whatsoever in the horizontal plane and only the miniscule tracking weight resistance in the vertical plane.

11. With overarm placed over spindle, play repeats even with only a single record.
Overarm not dropping fully after record has dropped from stacker.

12. Tonearm returns to its rest after play but deck does not shut down.
Below-deck mechanism fouling, jammed or restricted by hardened grease.

13.
I have a non auto, single play, machine but the motor won't start.
A common means of starting the motor on these machines is to lift the tonearm from its rest and move it to the right. This operates a switch to start the motor.

14.
Speed change control jammed or excessively stiff.
Gummy oil and/or grease on the cam mechanism and it's linkage which raises and lowers the idler wheel to effect the speed change. See fourth image in post #9; this cam and its linkage can be seen below and to the left of the motor.

15.
Tonearm bounce. This can be a nuisance on some, especially BSR, decks. As records drop from the stacker the deck suspension springs react, causing the whole deck to tremble. This in turn causes the tonearm to bounce, especially when tracking weight is light, and jump or skid as it lands on the record. The BSR UA15 deck fitted to the Pye 1005 can be very prone to this. The cure is to remove the deck to gain access to the suspension springs, then stuff a lump of foam rubber/plastic inside the springs to give a damping effect. Garrard tended to do this anyway, BSR apparently sometimes did and sometimes didn't. Either way, the type of foam originally used tended to perish away over the years. The ideal foam to use is the type found on those yellow things you use for washing up, with the green scouring pad on one side. See also the later post on Collaro decks.

Many of the above problems are caused by lubrication issues, namely gummy oil and dried-up grease. As the oil/grease problems are covered in following posts and other forum threads (linked to where appropriate) we'll now focus upon a few specific issues in the following posts.
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Old 9th Oct 2011, 5:05 pm   #6
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Default The deck, specifics Part 2.

Idler Drive
The vast majority of old record players are 'idler drive' machines. This does exactly what it says on the tin; drive (from the motor) is transferred to the platter (the round thing you put records on) via an idler. Note that the idler wheel is sometimes known as the "jockey" wheel.

To accommodate different speeds, the motor spindle is stepped. Three or four steps may be encountered, rarely two.

The speed selector moves the idler up and down so that it aligns with the spindle step corresponding with the chosen speed. The largest step corresponds to the fastest speed, typically 78 rpm; the smallest corresponds with the slowest speed.

The operation control not only applies power to the motor, it also moves the idler so that it touches both the motor spindle and the inside of the platter.

Here we can see the idler of a three-speed record player with '33' selected and the the operation control set to 'off' and 'on' respectively. In the 'off' position, the idler isn't in contact with either the motor spindle or the platter, but it is vertically aligned with the smallest step on the spindle. In the 'on' position, the idler is in contact with both the spindle and the platter.

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Similarly, here we can see the idler with '78' selected and the the operation control set to 'off' and 'on' respectively. As before, in the 'off' position, the idler isn't in contact with either the motor spindle or the platter, but it is now vertically aligned with the largest step on the spindle. As before, in the 'on' position, the idler is in contact with both the spindle and the platter.

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What can go wrong
  • The inside of the platter and/or the motor spindle are dirty or contaminated with lubricant by some moron spraying WD40 wildly over everything on the assumption that a water dispersant carries magical repairing properties. The cure is to thoroughly clean both the stepped motor spindle and the inside of the platter (don't forget this bit just because you removed it and have the short-term memory of a goldfish) with IPA (isopropyl alcohol.) This is often the cause of slow or varying speed as the idler slips on the motor spindle and/or platter; it often causes the deck to grind to a standstill during an automatic change cycle.
  • The idler's surface has become hardened, glazed or crazed with age. As the diameter of the idler does not have any bearing on the deck's speed whatsoever, it is possible to remove the hardened/glazed surface with very fine abrasive paper without it affecting the speeds. The easiest way to do this is to spin the idler using a lathe or electric drill. This, too, is often the cause of slow or varying speed as the idler slips on the motor spindle and/or platter; it often causes the deck to grind to a standstill during an automatic change cycle.
  • The rubber motor mounts have decomposed, allowing the motor to drop lower than it should be, causing mis-alignment between the idler and the correct step on the motor spindle. There are several methods to solve this problem depending on the particular deck, so it may be better to ask. This is often the cause of "it plays at the wrong speed" faults.
  • The idler fails to make contact with either the motor spindle, the platter or both when the deck is set to operate. This is often caused by the arm which carries the idler being stuck. It should be free to swing back and forth. Dismantling, cleaning and lubricating is the cure. This problem results in a running motor but a platter which doesn't turn.

Belt+Idler drives

Ignoring more modern and professional decks with belt drive, there exist a small number of older decks (notably by Garrard, such as the RC80M to name one) which use a combination of belt and idler drive. In these, two small belts and an intermediate pulley are used to transfer the drive from the motor to the idler wheel.

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The required belts are becoming difficult to obtain in the UK and Europe, but are currently obtainable online from the USA. A web search will show a number of suppliers.
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Old 15th Oct 2011, 8:47 am   #7
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Default The deck, specifics Part 3.

Record changer lubrication.

As many of these are half a century old, with the grease and oil of the same age it’s not surprising that trouble will arise.
If you only have one of these to overhaul, there’s no need to spend money on greases and oils that you might already have, so we’ll give a quick breakdown on this, followed by some detail. Preferred lubricants are in bold, but others will suffice:
Sintered bearings in motors, idlers and turntable bushes. 3 in 1, sewing machine oil, thin engine oil. Not clock oil.
Ball races. Any light grease, silicone grease, Vaseline.
Pickup spindle and arm bearing. Clock oil, 3 in 1, sewing machine oil, thin engine oil.
More details below.

Sintered bearings:

These are made from bronze dust compressed into a bush, so they appear to be solid, but are actually porous so they can soak up lubricant a bit like a sponge. Most motor bearings have sintered bushes surrounded by a felt ring which is soaked in oil
Commonly, sintered bearings are used in motor bearings, idlers and the large bush on the turntable spindles.
Quite often, someone has used grease or thick oil on these when they’ve dried up; probably solves the immediate fault, but means it will soon need lubricating again, and to do it properly, all the grease and other gunk will need soaking in petrol, IPA or similar cleaning fluid (not paraffin).
Ideally these bearings need heating, as does the oil. As the turntable and idler are difficult and inadvisable to move, just warming the oil in a metal container and leaving it to soak into the bush should suffice.

Ball races:

Commonly used on the turntable and sometimes on the pickup spindle. Wash out and apply light grease.
Various parts of the autochange mechanism like the cam gear track and spindle need greasing; the best ones are heavy greases like Molyslip or water pump grease, but anything from a motor accessory shop ought to do.
It is very important not to lubricate the parts of a velocity trip, nor any sliding bar that operates it from the pickup rotation.

The ideal to strive for might be to dismantle the entire deck, clean off everything and respray the various painted parts, but that might be after the first dozen you have repaired, and you will need to take lots of pictures! This is a convenient point at which to mention....

Deck underside mechanics:


Although most problems with slow/stiff/seized decks can be attributed to trip pawl, cam and motor bearing defects, the mechanics on the deck's underside can also need attention from time to time. Refer to the images in post #9 to see what it all looks like under there.

Present are lots of arms, linkages, plates, springs, circlips and grease; the latter in various states of usefulness or uselessness as the case may be. Complexity also varies, as mentioned elsewhere.

If, and only if, you're convinced the mechanics need attention, you can remove the deck (making careful note of where any disconnected wires should go) and operate it by hand in order to see how the mechanism functions. Remember to release the tonearm from its rest and take steps to ensure the tonearm isn't allowed to swing about unchecked and become damaged. Temporary removal of the stylus is also a wise idea.

Look for broken, missing or overly slack springs, same with circlips. Look around for hardened grease and for any foreign bodies which may have become jammed in the mechanism. On that latter point, it's surprising what is often found inside record player cabinets; old styli, old cartridges, paperwork, record and stylus cleaning brushes and so on. When a portable machine is turned onto its side for storage or transportation, these objects can easily find their way into the mechanism and become lodged therein.

So if you do find the need to dismantle all or part of the mechanism, familiarise yourself as mentioned above, make careful note of where everything goes - taking photographs if need be. If the reason is only degreasing and regreasing, you can often dismantle just one or two parts at a time as necessary. Hardened grease can be scraped off and any residue removed with WD40. For regreasing, any automotive grease is fine.

On the subject of WD40, as mentioned, this is good for removing old grease but ensure the WD40 doesn't go all over the show and remove all traces of it once it's done its degreasing work. A good idea is to spray some WD40 into an old cup and use an old toothbrush or fairly stiff artists paintbrush to work the fluid into where it's needed. Obviously, keep plenty of old rags to hand and use them frequently as you go along.
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Old 19th Oct 2011, 10:06 pm   #8
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Default The deck, specifics Part 4.

Turntable speed and the (mains powered) motor

Your record player should run at a speed within +/- 1 or 2RPM (Revolutions Per Minute) of the record speed it's been set to. Any greater deviation can be detected by those with a sharp ear and, indeed, even a 1 RPM deviation can be detected by those determined to do so, depending on the record being played.

Typically, your domestic mains-only record player will be fitted with what's known as a 'Shaded Pole' motor. These motors are, to a degree, susceptible to load variations and the ups and downs of the mains frequency. The latter, though, isn't such a nuisance nowadays as it tended to be at one time - not that it was ever really a major nuisance.

However, with reference again to the importance of correct lubrication/maintenance and cleanliness, your record player should do its job perfectly acceptably and with no real cause for complaint. This means clean and properly lubricated motor bearings, idler wheel bearing and turntable bearing. The turntable should not be fouling on anything (for example, something dropped down between turntable rim and deck plate) and the stylus tracking weight should be correct although a gram or two will make no difference in this context.

If you wish to check the speed for accuracy, you can do so with a 'strobe disc'. This link provides one you can print out and others can be found via a web search. You need to ensure the disc is for use with the mains supply frequency for your country (eg 50Hz in Europe, 60Hz in the USA and Canada) and you also need a mains powered filament light bulb operating at fairly close proximity when you use the strobe disc. In use, fix your eyes on the strobe disc and if the speed is correct the disc will appear to be stationary. Any deviation from the set speed and the disc will appear to move slowly in one direction or the other.

Caution: If you suffer with Epilepsy it might be wise to avoid using a strobe disc. I'm not medically qualified so don't know if any risk exists or not, but I feel it's as well to mention it.

Finally on the subject of speeds, be aware that not all 7" records run at 45RPM (45.1 to be pedantic), some are 33RPM (33.33 to be pedantic again) and a few 16RPM (16.66) examples also exist. Be aware, too, that what you assume to be a 78RPM record might not be; at one time all sorts of odd speeds existed, 74RPM, 80RPM to name just two. The uninitiated can easily be caught out by this, believing incorrectly that a fault exists with the record player.

Moving specifically onto the motor now; as previously mentioned, your record player is most likely to contain a 'shaded pole induction motor' (for convenience, "SPIM"). "Induction" means the motor does not make use of carbon brushes. SPIMs are a type of, but not a literal, synchronous motor. Motor speed (which is constant irrespective of turntable speed) is governed by the frequency of the AC mains supply. For this reason (different voltages aside) motors designed for 50Hz supply are not suitable for use on 60Hz supplies and vice versa. See the next post for just such a situation and the usual solution.

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^ Not the best of images, apologies for that, but here we can see the familiar BSR SPIM as fitted to a later BSR deck (C129 I think it is). The plastic housing (1) contains the field coil, which is nothing more than a hollow bobbin carrying a winding of insulated copper wire. Through the bobbin passes the approximately horseshoe-shaped pole pieces (2). Although this is seen as being one component, making "pieces" something of a misnomer, it is in fact several thin plates rivetted or bonded together. Problems can occur here with plates working loose and causing unwanted high-pitched rattles, almost a buzz, although this is extremely rare with record player motors. It's more common with transformers which use a similar construction method - usually known as "laminations". Should you encounter the problem, a generous application of, say, varnish usually sorts it out.

Upon the poles is mounted a bracket (3). On this bracket is located one of the motor bearings at (4). This image shows the underside of the motor; there is a similar bracket and bearing on the topside but whereas the underside bearing is blind, the topside bearing isn't. This is to allow the rotor shaft to extend through for the fitting of the stepped drum from which the idler wheel is driven. The rotor is just visible behind the bearing (4). Note that this type of motor has a 'rotor' and not an 'armature'.

For readers familiar with synchronous clocks, the layout of the motor above will be familiar as it is similar to motors found in many such clocks, notably Metamec and Ferranti. Smiths clocks, at least until their later years, mainly used a different type wherein the coil (stator) completely surrounded the rotor.

See also post #13 regarding motors.
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Old 19th Oct 2011, 10:06 pm   #9
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Default The deck, specifics Part 5.

A brief insight into Collaro decks

These decks differ to the BSR and Garrard types which this guide has featured so far. Quite fascinating to watch in action are the Conquest and Studio models; the tonearm itself feels and sets the record size before the actual play cycle begins.

Michael Maurice has produced a very good illustrated guide to servicing the Conquest here. It is therefore not intended to go into any great detail herein, so what follows is merely for comparison purposes with other decks within this guide. This website may also be of interest.

Michael has also produced a most frightfully useful guide to the Collaro Studio here.

Collaro also manufactured decks which were more conventional in operation; the RC54 and RC456 to give two examples (of those two, the former is 3-speed and the latter 4-speed). Despite the relative complexity of Collaro decks, possible faults and their cures are pretty much the same as other makes of deck.

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^
This image shows a tatty old Portogram record player fitted with a Collaro RC456 deck. This deck differs to the Conquest in that it has a more conventional 'finger' to detect record size, otherwise it's essentially similar. Of interest is that this Portogram has a 110V 60Hz motor, for the USA market, but has been converted for use in the UK. See next images.

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^
The lefthand image shows a Collaro speciality - twin idler wheels. The wheel on the left drives the turntable, that on the right drives the auto cycle. Although this makes the mechanism somewhat more complex, the idea was to allow the cycle to operate at the same speed regardless of turntable speed. Nice idea because other makes of deck look quite absurd during the autochange cycle at 78RPM; BSR decks in particular can be prone to tonearm bounce, as a result of records dropping, at that speed due to their relatively soft suspension.

Mention was made above about the USA - UK conversion; note the stepped pulley is a blue colour. This is part of the conversion and compensates for the difference in motor speed due to the 10Hz difference in mains frequency, so should you come across a blue pulley this is the reason for it. "Pulley", incidentally, is a misnomer but it's in common use nonetheless. "Stepped drum" would be a more accurate term. (It's appropriate to mention at this point that BSR sometimes used a different pulley arrangement; 78RPM was a seperate component whilst other speeds were machined into the motor shaft.)

The centre image shows the mechanics on the underside of the same deck. Note the relative complexity and also the cam mounted on the underside. The righthand image (courtesy of Mike Phelan) shows the underside of a Garrard 3500 deck and is included for comparison.

Towards the bottom of the centre image can be seen a brown Bakelite switch, this feature is common to all autochanger decks. As will be obvious, this switch connects and disconnects the power to/from the motor. It is operated via mechanical linkage from the Start/Auto/Reject control when starting and via the mechanical shutdown mechanism at the end of play. These switches rarely give trouble although it's not unknown. So if power is there and the controls feel like they're working OK yet the motor won't start, it's worth checking this switch and the wiring to it before looking at the motor itself.

Once again, due to Michael's post, linked to above, we needn't say anymore here about Collaros. However, should you encounter a problem which this guide or Michael's doesn't cover then please create a new thread for that purpose.

Finally for this post, something of an amusing irony quoted from a service sheet concerning Collaro decks:
Quote:
The autochanger mechanism is designed to be as foolproof as possible. In addition, liability to breakdowns due to wear and tear is reduced by utilising the minimum number of actual working parts.
Minimum number? compare the Collaro to the couple of other makes of deck illustrated in this guide! In fairness, however, as relatively complex as Collaro decks appear to be, they tend to give less trouble than other makes of deck. The Trip Pawl mechanism, in particular, generally operates reliably and with little need for attention.
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Old 19th Oct 2011, 10:06 pm   #10
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Default Valves, mains power supply and amplifier components.

Valves

It simply isn't practical here to describe each and every valve (vacuum tube), what it does and how it functions. However, the beginner needs to recognise the handful of types found in the record players which this guide embraces. Take, say, your run-of-the-mill Dansette or Fidelity machine; you may find a solid state rectifier and just one valve (an Output valve driving the loudspeaker), or you may find a rectifier valve and an output valve, or two output valves and an amplifier valve preceding the output valve. You will need to know which is which and, importantly, where they locate on the chassis/PCB. On the latter point, it's not uncommon for the 'phantom twiddler' who doesn't know what he's doing to twiddle about and insert valves in the wrong sockets - then wonder why the machine fails to function. The problem is quite common with radio receivers but isn't unknown with record players. Service data or, often, a diagram inside the cabinet, will show you where the valves are located.

To make things easy we'll stick herein to the more familiar valve codes as used by Mullard and a few other manufacturers. Codes can be cross-referenced via valve equivalent books or, perhaps more conveniently, via websites such as http://www.r-type.org

In the main, record players designed for AC mains (only) power will use valves with codes beginning with the letter 'E' whereas record players designed for use on AC/DC supplies will use valves with codes beginning 'U'. A few examples follow:
  • EL41 and EL84. These are Output valves for AC supply.
  • UL41 and UL84. As above but for AC/DC supply.
  • EZ40. Rectifier valve for AC supply.
  • UY85. Rectifier valve for AC/DC supply.
Note that if the second letter is either a 'Y' or a 'Z' then the valve is a rectifier.

Other valves found in record players from the period in question might include:
  • ECL82
  • ECL86
  • PCL82
  • PCL83
  • UCL82
  • UCL83
The above are Audio frequency/Audio amplifier valves. The two PCL's are actually, or rather were originally, television valves. Ignoring rectifier valves obviously, you may find your record player contains two identical valves. If this is the case you'll have what is known as a "Push Pull" output stage. However, to further describe this here would be drifting somewhat so we'll elaborate in a later post concerning P-P output stages and stereophonic machines (the two are not necessarily the same thing). Meanwhile, hereinafter, you can assume we're talking about the more common single-ended (ie single output valve) amplifiers.

However, before we press on to amplifiers proper further down this post, one further explanation would be in order. Beginners may by now have realised that Output valves are the ones which ultimately drive the loudspeaker. Some confusion may therefore arise when a valve such as an EL-something, or a UL-something is not present, but ECL - or UCL - type(s) are present on its, or their, own. This is because valves, put simply, are in fact two or more functions in one glass envelope - hence diode, triode, pentode and so forth. So if we take, say, an ECL82, this valve on its own acts as a preamplifier and an output valve; E = for AC supply, C = the preamp section and L = the output section.

The same applies to, say, a UCL82 with the exception of the "U" which, as you'll recall, signifies use in AC/DC machines. You cannot, therefore, mix E and U series valves on the same chassis irrespective of the remaining letters and numbers of a valve's code. Out of interest, there exists one or two odd expections to this in the radio world but you won't come across it in record players.

Valve and valve base faults

There exists, among 'Joe Public' an erroneous assumption that almost any fault with any valved equipment has to be down to a faulty valve or valves. This is probably an assumption stemming from the fact that valves are, since 1930-ish anyway, the only components which can be readily unplugged from and reinserted into a chassis.

Nevertheless some problems can - and do - occur with valves from time to time, albeit far less so in record players when compared to radios. This is because; record players usually contain less valves, because record players tend to see less use than radios and because record players usually have fewer other components which can instigate valve trouble. The latter, of course, is rather an obvious statement because the number of "other components" is directly related to the number of valves and the function of those valves.

Common and easily traced and remedied valve faults include:
  • Identification Perhaps not strictly a fault but a commom problem with valves is the inability to identify them due to the markings on the envelope being invisible. You won't get very far if you can't identify your valves. A common 'cure' is to place the anonymous valve in the fridge for a while, then breathing on it in the hope that the ghost of the markings will show up. If they do, then writing the details on the envelope with a CD marker pen is the usual next step. A quicker and better idea, however, is to shine an LED torch onto the valve. In 99% of cases the markings thus become visible - or at least the imprint of where the markings once were becomes visible.
  • Valve totally dead and not 'warming up'. Assuming none of the faults described below apply, the valve most likely, although not unquestionably, has a failed heater. Substitution will prove or disprove this, but first it's wise to grab your meter and check for voltages at the valve base. To do this you will need to obtain - and understand - valve data. Of course, you can use your meter to check heater continuity by first ascertaining which two pins connect to the heater. Be careful your meter doesn't pump more current into the heater than it's designed to handle though. If you have any uncertainties regarding this and/or any uncertainties about LT and HT supplies you're advised to seek help in the forums.
  • Lost vacuum. A valve (or vacuum tube) consists of a glass envelope, expelled of air, within which the electronics are located. A valve which has lost its vacuum will have a milky on the inside if its envelope. Replacement of the valve is the only solution.
  • Dirty valve pins and/or base sockets. Clean by spraying the base with switchcleaner spray and plugging in/unplugging the valve several times. This MUST be done with the mains supply isolated and do not reconnect the mains until the switchcleaner has dried.
  • Bent or broken valve pins. Assuming the valve to be 'all glass', you can straighten a bent pin be careful bending with your fingernail. This does, however, carry the risk of the glass cracking and the valve thereby losing its vacuum. Purpose designed gadgets for straightening valve pins were made but they're now scarce. Should you fail to remedy the problem, replace the valve. Same for broken pins, replace the valve - unless the broken pin happens to be an unused one.
  • Poor or non-existent connection(s) between valve pin(s) and base sockets(s). Assuming the valve pins to be in good order, this problem is usually the result of the socket(s) for some reason opening up and thus not contacting the pins. You can attempt to close up the affected sockets but they tend to break. If this happens, replace the base.
  • Tracking across valve base. This is the same as the tracking which can occur across the distributor cap of a petrol engine. Sometimes this can be cured simply by thoroughly cleaning the valve base, but sometimes the problem can persist and the easiest solution is to replace the base.
  • Internal short circuit. One or two valves can develop such between the heater and cathode. The most well known valve for this problem is the UL41. Replacement is the only solution although, perhaps fortunately, you're unlikely to find many record players which contain a UL41.
  • Low emission. Put simply, this means a valve is not pumping out what it's supposed to. Like Selenium rectifers, rectifier valves are not immune to the problem either. Replacement is the only solution. Perhaps I should add here that "emission" is a term more often applied to valves other than rectifiers. "Low output" would perhaps be more appropriate for a rectifier valve, but I stuck with "emission" to avoid any confusion with Output valves.
  • In connection with the low emission problem described previously, one point is worth a reminder. This reminder being that a defect with a valve can be, and often is, caused by faulty associated components such as capacitors. This is one reason why old capacitors (and resistors) cannot be ignored. Output valves are especially vulnerable to capacitor problems.
Power supplies, progressing onto amplifiers

The distinction between the power supply and amplifier if, say, the mains transformer is excluded, can become blurred. For example, some may see a smoothing capacitor and a rectifier as being part of the power supply whereas others may see these components as part of the amplifier. To sidestep this distinction and to assist newcomers in recognising components and their possible faults, this post is component, as opposed to unit, orientated.

At this point we are dealing with mains electricity, so if you are unfamiliar with this area, or cannot recognise components and/or understand their function, you are strongly advised to leave well alone and seek advice. Although much of it revolves around radio receivers, reading this and other pages of our main website will help you to understand components and their function. Pay particular, but not exclusive, attention to the capacitor section; illustrations within which will help you identify the different types and also recognise the potential troublemakers.

So what, you may be asking, has radio-orientated stuff got to do with record players? A fair amount is the answer; what you'll find inside your run-of-the-mill record player is effectively the power supply as found in a mains powered radio, married to an audio output stage as also found in said radio(s). Indeed, many radio receivers include a facility by which an 'add on' record deck can be connected to - and thus played through - a radio receiver. In such instances the radio receiver is then, for all intents and purposes, serving exactly the same function as a record player amplifier. Therefore, many power unit and amplifier components found in radios will be the same as, or similar to, those found in record players. For the moment, however, we'll stick to mains power supplies.

Put simply, this will consist of a mains transformer (if an AC mains only machine) or a dropper resistor (if an AC/DC mains machine), a rectifier (which may be a valve or a Solid State device) and smoothing/reservoir capacitors. In some circumstances the supply for the valve heater(s) may be via a tap off the motor windings. If the motor has three wires connected to it, then this will be the situation.

Regarding mains transformers, usually an 'isolating transformer' is used. This type, in simple terms, has two coil windings; one primary and one secondary. The windings are inductively coupled and thus 'isolated' from the mains power source. Beware though, on rare occasions an 'autotransformer' may be used and I've come across at least two record players so fitted (one being an Emerson). Autotransformers are little more than a large wire-wound resistor and do not, therefore, offer the aforementioned advantage of isolation.

The mains dropper resistor takes the place of a transformer in AC/DC machines, the latter meaning a machine designed to operate from either Alternating Current or Direct Current mains. There are various reasons for the provision to operate off DC mains but these are beyond the remit of this guide. What you do need to be aware of, however, is that AC/DC equipment (as with equipment using an autotransformer) is potentially more hazardous than AC-only equipment. This is especially so if your record player has a metal chassis (often a PCB is used though).

So it will by now be understood that should you need to do any work on your record player's electrics, you need to be armed with knowledge of what in fact you're dealing with - another reason to be familiar with the various components. Otherwise the relevant service data as advised back in post #1 will tell you, as will a little data plate affixed somewhere on the record player (these are not always present though).

A vaguely similar power supply arrangement to that of AC machines will be found in mains powered transistorised machines, with the obvious difference that there'll be just a low voltage supply to the amplifier but not necessarily to the motor - so beware.

At this point it's convenient to elaborate upon why power supplies and amplifiers are combined in this one post. See the image below.

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^ Here's the reason, power supply and amplifier components are mounted upon a common chassis - with the exception of the mains transformer. It is probably, therefore, an idea to seperate the components by explanation. This is a typical arrangement for AC machines although, as mentioned earlier, a PCB (Printed Circuit Board) is often used instead of the far better aluminium, or aluminium alloy, chassis seen here. On AC/DC machines using a dropper resistor, the dropper will likely be mounted on the chassis rather than seperately elsewhere as per the mains transformer. The reason for this will be explained shortly.

The image above shows what is, by domestic record player standards, rather a deluxe set-up. There are three valves; a halfwave rectifier (to convert the AC mains to a form of DC), an audio input amplifier and an output valve. That latter is the device which drives, via the output transformer, the loudspeaker.

Output transformers may be located on the chassis, as in this case, or on the loudspeaker itself, or on its own somewhere else within the cabinet. If you're a newcomer to this malarky, do not get the mains and output transformers mixed up! Also, do not run the amplifier with the loudspeaker disconnected unless a load such as a test meter is connected to the 'speaker wires.

At the bottom left of the image we can see the mains transformer, well away from the chassis. This component is mounted here for two reasons; 1. It facilitates the fitting of different transformers according the which market the machine is intended for, thus allowing the chassis to be of a fairly standard design. 2. Keeping the mains transformer away from amplifier components helps reduce the risk of induced mains hum.

This transformer provides LT voltage for the valve heaters (LT = Low Tension) as well as the feed to the rectifier, via a surge limiting resistor, which emerges as the HT (High Tension).

Moving to the chassis proper, at its left we can see a pilot lamp which tells us when the power is switched on at the on/off switch. This latter is combined with one of the two potentiometers seen next to the pilot lamp. Next we can see a large cylindrical alloy can. This is the reservoir and smoothing capacitors; the purpose of which is to smooth out the hum caused by alternating current mains. The rectifier alone cannot do this. At the bottom of the chassis can be seen the three valves, one of which is the rectifier (Rectifiers are called 'valves' for convenience. In this case the chassis contains, from the technical viewpoint, two valves and a rectifier. This would commonly be stated on technical data as being "2v + R". Do not confuse "2v" with "2V", the latter meaning "Two Volts").

Behind the chassis and thus out of view in the image lurks a bare minimum of other components, namely two or three capacitors and a couple of resistors. All very simple when compared to, say, a radio receiver. The components described in the above three paragraphs are to do with the power supply and we'll continue with some specific issues in this area.

Smoothing 'cans', as they tend to be called, should be treated with respect. Examine them at their solder-tag end; is that end 'pregnant' ie bulging? is there any mould or goo-like substance around the solder-tags (terminals)? If any of these visual faults are present the 'can' must be replaced as it's in a dangerous condition and could literally explode, resulting in at least a vile mess or at worst physical injury to yourself. These 'cans' are another reason you should not apply full mains power to a machine with an unknown history.

The failure to smooth out mains hum is another indication of a failed smoothing can, although in some cases the can may just need 'reforming'. Do a search for "Reforming", "Reforming electrolytics" etc. Although it's mentioned elsewhere, it is convenient now to repeat that with many mains powered record players a degree of 'warm' background hum is normal. Get hum thanks to a duff smoothing can and you'll know it - a very loud hum not unlike the sound of muffled, but very rapid, machine gun fire. Another aspect relevant here is 'Ripple Current'; rectifiers leave behind what you could call a 'residue' from the ingoing AC current. To handle this, capacitors have a 'Ripple Current Rating', quoted in mA (milliamps). Determining ripple current is really not something the beginner, so if you find yourself needing to replace some electrolytics it's easiest to select the highest rating for the voltage and capacitance you require. That said, most modern replacements seem to be perfectly adequate regardless so it probably won't be an issue you need to lose sleep over.

Finally on the smoothing can subject, another safety issue. When a machine has been powered up, these cans can retain their charge for a while after power has been disconnected. Therefore NEVER touch the terminals of these cans, or any other parts connected to them, for some minutes following power disconnection. A discharge resistor may or may not be present, either way take no chances as belts from these cans are nasty and potentially lethal.

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^ A little while ago we talked about mains transformers. With machines designed for AC/DC power supplies (that's AC or DC) you will find not a transformer but a 'Dropper resistor' (simply "dropper" hereinafter). The image on the left shows a typical dropper BUT one removed from a radio receiver. This type is mounted on, and perpendicular to, the chassis/PCB and has connection tags to suit various input (ie mains) voltages.

You may find this type of dropper inside an AC/DC record player or you may find a simpler 'fixed input voltage' axial type such as that shown in the image on the right. However, the latter type can be found elsewhere on the chassis for ballasting purposes so don't get confused (Earlier it was mentioned about some more capacitors and resistors being out of sight behind the chassis depicted; one of them is just such a resistor).

Droppers/ballast resistors are high power devices and thus run hot, very hot in fact. "High power" refers to their Wattage ie Volts x Amperes = Watts = Power. It is worth adding here that Output and Rectifier valves also run hot and this is normal.

Should a dropper fail, and they do fail, you have various options available to you. Should you find yourself in this position, plenty of information exists in our forums and main site. Alternatively and especially if you're unsure of what you're doing, you can create a forum thread to seek advice.

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^ In the rectifer department we've so far babbled on mostly about 'valve' rectifiers. Many old record players, and other equipments, will instead make use of a selenium rectifier. A 'Solid State' rectifier in other words. This image shows a typical selenium rectifier which, as it happens, was once installed in a record player (some joke of a low quality 'attache case' effort I believe it was). Other rectifiers (metal oxide) take the form of ganged discs with fins for air cooling, the flat Selenium type as illustrated are affixed to the (metal) chassis which cools by conduction ie the chassis acts as a heatsink. You will therefore not find flat selenium rectifiers PCB mounted.

Selenium rectifiers, being solid state, have some advantages over the 'valve' types. Unfortunately they can go wrong - and they do. The symptom of impending failure is low output, meaning the voltage output is lower than what it should be, but if a rectifier has reached this state then it's scrap anyway - impending total failure or not. Total failure cannot be mistaken as very unpleasant odour is emitted - and the fumes are toxic. Do a forum search for "selenium rectifier" and "rotten eggs" and you'll get the idea.

Failing or failed selenium rectifiers can easily be dealt with by replacing them with modern, easily obtainable diodes. As aforementioned, searching for "selenium rectifier" will give the details. If your amplifier has poor, or no, output, distorted audio and/or poor bass control (if fitted) one of the things you should check is the rectifier output. Set your meter to a range of at least 250V and check across the rectifier's output. Remember you're dealing with high voltages here, with AC mains in and DC output at, if all is well, a figure (voltage wise) approaching that of the input. If the output is less than 200V, the rectifier is failing.

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^ We'll move onto amplifier components now. This image appears earlier in this post but is repeated here to avoid the nuisance of repeated excessive scrolling of a long post.

As touched upon earlier, if you take the chassis of a radio receiver and rid it of it's RF and IF stages (look those up if unsure) you're left with just the audio and output stages. In very simple terms, this is what's inside a record player - or at least in the case of the example used in the images here; some really cheap, rubbishy offerings contain little more than an output valve and a few capacitors and resistors.

It is impossible to describe here how an amplifier works simply because amplifiers vary. For example, there may or may not be a tone control or there may be seperate bass and treble controls. There might be a single valve or there maybe two or three. The output may be mono or stereo (the latter is somewhat rare where portable domestic record players are concerned, but machines with the facility for an add-on speaker/amp unit for stereo reproduction are quite common).

So to simplify things, given too that we have only one amplifier picture to refer to, we'll give just a basic description of how the amplifier depicted functions. Remember that of the three valves seen, only two are part of the actual operation of the amplifier.

To begin, we can see a white cable descending to the amplifier. This is the wires from the cartridge, carrying the signal from the record to the amplifier. These wires connect to the volume control which, in this case, also incorporates the on/off switch. Across this is connected the tone control and its attendant 'top cut' capacitor. From here we have the 'input signal'. This signal then passes to the first valve (V1) where it's amplified. This stage is, in effect, a 'preamp'. From here the now-amplified signal passes to the second valve (V2, the output valve) where it is further amplified. The next stage is the 'output transformer'; this can be seen mounted at top right of the chassis. The signal is fed to the primary winding of this transformer, thence to the loudspeaker via the secondary winding.

As mentioned earlier, a small few resistors and capacitors also lurk for coupling and other purposes. Capacitors are well documented here and elsewhere but resistors, other than mains droppers (which are wire-wound) are worth a mention. Carbon resistors, especially high value examples, tend to go out of tolerance with age. Specifically they increase in value. This can cause all sorts of apparently strange problems and, as the common-or-garden record player contains only a minimum of components, it's quick and worthwhile to do a check of all resistors.

If you can't read resistor colour codes (some have their values actually marked on them) then you'll need the relevant service data, which will tell you values and locations. You can check resistor values in-circuit providing no other components are connected in parallel with them. Once again, service data will give you this information or, if data isn't available, a careful visual examination of the circuit will tell you. This isn't daunting on relatively simple record player circuits (as opposed to the far more complex radio circuits) but be aware that anything connected in parallel with a resistor may not necessarily be located slap bang next to it on the chassis/PCB.

If we divert for a moment and go to post #14, take a look at the second image therein which shows part of a transistorised amplifier. At the foreleft of the image can be seen a small low wattage resistor. This is one of those mentioned above which have the value printed upon them, in this case 10K (10,000 Ohms). The main reason for this momentary diversion is to highlight a problem which can occur with this type of resistor; namely the crimped terminals. These can go intermittent or fail completely, the only real cure being to replace the resistor. This type of resistor is common in transistoried equipement - far less so in valved. In fact, off the top of my head, I can't say if they appeared in valved equipment at all.

Another not uncommon fault with resistors is a peculiar and otherwise unexplainable, rustling sound at the loudspeaker (Dry solder joints, wiring faults etc usually materialise in the form of louder, harsher, crackles and pops). If you encounter this problem with a resistor, replacement is the cure.

The Push-Pull amplifier

Generally speaking, the type of record player this guide is concerned with will have a single output valve. Better quality machines may have a pair of output valves of the same type (in transistorised amplifiers a pair of output transistors is virtually the norm, albeit not necessarily of the same type; one PNP and one NPN for example).

Sticking with the Push-Pull valved amplifier, the setup is rather more complex (and one reason we're not detailing stereophonic machines in any great detail). The signal, preamplified, goes through a 'Phase Splitter' circuit wherein the signal is split into phases; imagine an AC waveform with one side + and one side -, this means the two phases are then 108deg apart or, if you like, polarised. To provide superior performance (compared to a single valve [single ended] output stage), each phase is seperately amplified and hence the reason for the twin output devices ("Device" is a common term for a valve or a transistor in the context of a circuit).

That's the nutshell description, the reality being rather more complex in that output devices must be balanced (matched, hence the term "Matched Pair" [commonly applied to transistors] which you might have heard of) and biasing circuits must be precisely set.

To learn more, do a web search for "Phase Splitter" and "Push-Pull output stage". Don't worry if most entries concern guitar amplifiers as the principle is broadly the same.

Brief summary

Record player amplifiers do not, largely due to their relative simplicity, give too much trouble. When faults do appear, they can be out of tolerance resistors, leaking capacitors ("Leaking" means passing DC), dirty valve pins and sockets, dirty or otherwise faulty controls, 'dry' soldered joints and/or cracked tracks if a PCB type chassis is used.

Valves, contrary to popular myth, don't give too much trouble beyond the aforementioned dirty (or bent/broken) pins and sockets. There are, however, a small few exceptions but most of these are seldom found in record players.

Finally for this post, the keener eyed among you may have noticed the wire clips securing the valves in position in the above image. These should be handled with care; they're tough and can break the pip on the top of the valve, if not smash the glass envelope completely. Should this occur the valve is, obviously, scrap.
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Old 5th Nov 2011, 6:36 pm   #11
Darren-UK
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Default Cartridges and styli.

The forums are an absolute goldmine of information regarding cartridges and styli, so this post is as concise as is practical. As mentioned way back in post #1, "Stylus" is singular and "Styli" is plural - it is not "Stylii".

As described in earlier posts, one common problem with old record players is low, or non existent, audio. "Audio" means "sound, eg music, at the loudspeaker". This could be caused by low power due to weak valves or rectifier (low emission or output respectively), faulty potentiometer (volume control) but possibly the most common cause is a failed, or failing, cartridge.

How it all works is very simple. The record groove, or track, has a varying horizontal pitch (mono records) or a varying horizontal and vertical pitch (stereo records). The pitch is akin to a visible waveform in the surface of the record. This pitch causes the stylus to 'vibrate' as the tonearm follows the groove across the record. The stylus is screwed, clamped or clipped to the cartridge and the stylus shank sits on a tiny 'rubbery' seat which is located at the front of, and is part of, the cartridge. By this means, the 'vibrations' from the record are carried inside the cartridge.

Not infrequently we get members who are unfamiliar with record players and, perhaps understandably in the 21st century, are confused with the difference between a stylus and a cartridge. Looking at the second image below, the stylus is the white component marked ST8 and this clips into the cartridge which is the large boxy black component. This is the general arrangement but, as will be seen, the actual appearance of cartridges and styli varies widely.

At this point it's a good idea to briefly mention the different types of cartridge, namely crystal, ceramic and magnetic. We are concerned only with the first two in this guide but, more specifically, the crystal type. This is because the crystal cartridge is a) the type most likely to fail and b) by Sod's Law is the type found in the majority of old record players from the 1950's and 1960's which have not undergone any repairs of restoration.

The crystals are of Rochelle Salt and do not like dampness as this effectively turns them to goo and destroys them. Unfortunately many old record players which have just been dragged out and sold at last Sunday's boot sale will likely have been stored for years in just the sort of conditions which will kill a crystal cartridge.

So to return to our 'vibrations', these are converted by the crystal(s) into tiny electric currents which are invariably measured in, and quoted as, mV (millivolts). This is the signal which, via wires located beneath the tonearm, is fed to the amplifier and ultimately the loudspeaker to enable your treasured Arthur Mullard and Hylda Baker record to be heard by all your neighbours.

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^ These images show just three of the many types of now-obsolete crystal cartridge. The lefthand image shows a BSR X3 type cartridge minus it's stylus and this is convenient to show the little rubber 'seat', mentioned earlier, onto which the stylus locates. The centre image shows a BSR X5 type. These images also appear in the attachment here together with descriptions, so we don't need to repeat the information here. Perhaps needless to say, Philips were a law unto themselves and their peculiar cartridge contraptions are also covered therein, as well is in post #16 below.

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^ This image shows the BSR SC12H Stereo Ceramic High output cartridge. A Medium output version is also around. The cartridge illustrated is complete with stylus and the all-important mounting bracket (sometimes called the "mounting clip"). This cartridge is, at the time of writing, still available and is a common choice for replacing expired crystal cartridges. Be aware that some adaption may be necessary, not only for fitting but also the tracking weight may need checking and adjusting (more on this later). Other types can still be obtained including a small number of reproduction crystal types, but at a price when compared to the SC12 types. On the latter, shopping around is worthwhile as prices can, and do, vary.

Be aware that the SC12H may be of too high output for certain record players, depending upon the amplifier. If unsure then opt for the SC12M or check by creating a forum thread, giving the make and model of your record player.

But my old mono cartridge has two terminals on its rear and the stereo SC12 has four (two signal and two ground, one each per channel), you may well be telling yourself. Not a problem, see this thread.

One common head-scratcher (lice excepted), with a newly acquired, but old, record player with low, or no, audio is determining where the problem lies. The first thing to do is ascertain if the problem is a failed cartridge or trouble elsewhere. Very often it's the cartridge, if a crystal type is fitted.

The trick, assuming the machine is safe to power up, is to allow the machine to warm up (if valved) and turn the volume up to a high level. Touch, if possible, the terminals at the rear of the cartridge with the wires connected. It may be necessary, however, to disconnect the wires and remove, if present, the protective sleeves covering the terminals. Do this with great care as the wires and their terminals are fragile and repairing them can be extremely fiddly.

If the wires are disconnected, touch their ends. If a loud buzz emits from the loudspeaker the amplifier is very likely OK but the cartridge has failed. If only a weak, or no, buzz results you have an amplifier and/or power problem. Bear in mind that in this circumstance the cartridge may also be duff but, whatever and wherever, there will be a power or amplifier problem to deal with anyway.

Caution. On some basic, el cheapo, record players, the wiring to the cartridge may be electrically live to the HT and thus will give you a surprise jolt. Best to check first with a meter or a neon screwdriver IF you have one which operates at a suitable voltage range.

Should you wish to replace a stylus, a good range of these remains widely available - even for vintage machines. This is all well and good but many cartridges, as stated earlier, for vintage machines are obsolete and usually have to be substituted with something more modern.

The forums have many newcomers to vintage record players who seek a new stylus. Often they quote the make/model of their record player and ask "Where can I get a new stylus for a Bush so-and-so?". This is unhelpful because a) the make and model of deck is needed and b) what cartridge is currently fitted needs to be known.

The stylus, of which there are hundreds, is relevant to what cartridge is fitted. Obviously, therefore, if the original cartridge as specified when the machine was new has been substituted due to obsolescence then the current cartridge is the relevant detail.

A Google, or whatever, search will highlight numerous suppliers of styli around the world (and, to a lesser degree, cartridges). Pointing once again to our Vintage Audio section, we have a list of cartridge and styli supplies there. Here is the direct link.

Finally and conveniently overlapping the next post, if you have a crystal cartridge which is still in working order, you may care to consider changing it for a ceramic type anyway. Ceramic types generally track lighter and thus will cause less wear of your records. This is a matter of personal choice and, to a degree, a matter of opinion though.
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Old 9th Nov 2011, 12:10 am   #12
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Default Tracking weight.

Tracking weight is just another, but more common, term for 'stylus pressure'. This is, obviously, the pressure of the stylus on the record.

Back in post #4 we briefly described tracking weight and illustrated one means of adjusting it. Some record players have no means of adjustment, usually rubbishy single-play efforts, whereas some later decks have a weight at the rear of, and external to, the tonearm. These types are easily adjusted by means of a control with graduated scale. On machines with no means of adjustment, it only becomes a problem if a non original type of cartridge has to be fitted. In these cases it really is pot luck and you need to find a replacement cartridge and stylus with a recommended tracking weight matching, or very close to, that of the original. Tracking weights are often a little slack anyway, being quoted as 4 - 5g or 6 - 8g and so on.

So having decided you need to check and adjust the tracking weight for whatever reason, the big question is how do you do it when it's an older, or cruder, machine with no scale to read?

At one time various manufacturers produced what were commonly called "Stylus Pressure Gauges". The best known examples are those by Garrard; mechanical spring-balanced efforts of which older examples can probably no longer by relied upon for accuracy - not that they were that accurate to begin with.

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^ Not the best of images but it's included out of interest. The images shows a Garrard stylus pressure gauge "For microgroove records". I don't know its precise age but the original instructions which accompany it state that, at the time, Garrard still manufactured spring-driven deck motors.

It operates thus; the tonearm is positioned with the stylus resting on the little platform on the right. You then move the lever on the right, against spring pressure, to the point where the required stylus pressure is indicated on the adjacent scale. Next comes the tricky bit, you hold the lever at the required scale marking and check the indicator in the little oval window at top centre of the gadget. If the tracking weight (stylus pressure) is correct the indicator will sit midway in the window. If it isn't, you need to readjust the tracking weight on the tonearm, repeat the procedure - and keep this up until you get it right.

This particular gauge is no longer accurate enough for use (probably due to a weakened spring because of age) but I hang onto it as a collectors item, but you'll get the idea.

Not to worry though, stylus pressure gauges can still be obtained. Shure, for example, do them, although their range may be rather limited for older decks that track heavier. I don't know and can't be bothered to find out!

Alternatively you can obtain one of those little diddy digital scales to do the job.

"But I only have one or two record players and don't want to pay out for proper gauges, digital scales or whatever". That's perfectly understandable because unless you hoard or repair record players regularly you'll probably only use the gauge once or twice.

In these circumstances you can improvise to an acceptable degree of accuracy; so how about the following?

Grab a lollypop stick, measure and mark it's mid point, measure and mark two points - one at either end and equidistant from the mid point. Glue something suitable beneath the midpoint to act as a fulcrum; a piece cut off an old Biro refill for example. Dump your 'see-saw' contraption on the deck and let the tonearm rest with the stylus on one of the marked end points. Next, nick your wife's little metric weights from her kitchen scales, 1g, 2g etc., to the weight recommend by the cartridge/stylus manufacturer. If the see-saw balances, the tracking weight is OK. Otherwise adjust at the tonearm until it is OK.

If no such weights are to hand, you can do a reasonable - but probably not spot on - job using coins. Some examples of UK decimal coinage weights (Taken from the Answers.com website) are:

One pence: 3.56g
Two pence : 7.13g
Five pence : 3.25g
Ten pence : 6.50g
Twenty pence : 5.00g

Again, this range of weights probably won't achieve spot on results but it's better than nothing. This is especially so if the weight setting on your tonearm has for some reason been meddled with and gone way off the mark. If tracking weight is too light, the tonearm may bounce when it lowers onto a record and skid once it is on the record. Too heavy and the record may drag, especially if part of a stack, and damage to both records and stylus can and probably will result. In severe cases the deck motor can even be forced to run a tad slow. So in the absence of a proper gauge, the 'lollypop stick 'dodge, as comical as it may sound, could well save you a lot of agro.
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Old 9th Nov 2011, 1:32 am   #13
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Default Mains/battery and battery-only record players.

Apart from the obvious difference when compared to mains-only machines, these types differ in one other respect; namely the use of a DC can motor for the deck. Typically, these motors are designed for 9V operation and some may be in plastic housing but often in an alloy can (hence the name).

For some images of the workings of a battery-only record player, including its motor, see this thread concerning a Stella/Philips machine.

These motors often have a hidden secret, a speed governor. On the alloy canned motors, part of the can is designed to be slid off for access to the governor. On other, later, machines with plastic cased motors, governor access varies - if one is fitted. The purpose of the governor is to set the motor speed when the batteries are in good order, maintain the speed and, related to this, to prevent overspeed when batteries are new and thus a volt or so above their nominal rating. As batteries begin to fail the contacts will remain closed and this, to a degree, compensates for a small loss in battery voltage. See the images and their descriptions below for further details.

Battery and mains battery machines may have single-play decks (frequently) or autochanger decks (sometimes). In either case, faults causing slow speed are the same as with mains-only machines - the exception being the motor governor. If you have a problem which you think you've narrowed down to the governor, please create a dedicated thread with the relevant details as governor settings can be fiddly to correct.

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^
This image shows a DC can motor, this particular motor being fitted originally to a BSR GU7 deck. This same motor can also be found installed on a version of the BSR UA15 autochange deck for use in battery/mains-battery machines. Clear in this image are the three mounting points and their grommets, as mentioned earlier in connection with mains-powered motors. Also clear is the stepped drum (pulley), plus the two recessed screws which secure it to the motor shaft. This drum is a complete unit, as opposed to the type also mentioned earlier with which only the 78RPM section is a seperate component.

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^ This image shows the same motor with its cover removed (it simply pulls off), thus exposing the speed governor. The governor comprises a set of contact points similar to those found in a telephone dial or in the distributor of a petrol engine prior to the days of electronic ignition. The contacts are opened by centrifugal force, thus the entire governor unit rotates with the motor. The point at which the contacts open is regulated by the screw seen at bottom right. Once the motor begins to overspeed, the contacts open, cut power, close and reapply power. This happens so rapidly that the motor appears to maintain a constant speed, which it effectively does. At top left can be seen the little brass weight, upon which centrifugal force acts in order to open the contacts. The AA cell is there to prop the motor for the camera but also gives a size comparison; this little motor being powerful enough to drive an autochanger as mentioned in the preceding paragraph.

Moving on now, the record players in question are almost all transistorised* and most, but not all, operate from 9V (DC). On mains/battery machines there will be the usual transformer for AC mains input, rectifier (Solid State), smoothing capacitors and, hopefully, anti surge devices. On the battery side you'll find either two or more PP9's, 4V AD28's** or similar, or a bank or banks of 'D' cells. In fact almost any type of dry cells/batteries can be found but those mentioned are the commonest. Record players were even produced which used no less than four PP9's.

Obviously, mains/battery machines require a means of switching from one power source to another. This may, on later machines anyway, be automatic via the insertion/removal of a detachable mains lead or, more commonly, via a manually operated changeover switch.

Battery arrangements more often than not cater for one battery, or bank of batteries, powering the deck motor with another powering the amplifier. In a few cases, usually later and probably el cheapo machines one battery, or bank of, or two in parallel, will power the whole ensemble.

The two power sources and switching arrangements make fault finding very easy. Causes in italics:
  • Excessive hum.
    This can only be a problem with the mains unit.
  • Machine works on batteries but not the mains.
    No mains input, fault in mains unit, faulty changeover switch and/or associated wiring.
  • Machine works via the mains but not batteries.
    Faulty changeover switch and/or associated wiring, duff batteries, no batteries installed!, faulty/corroded battery connectors and/or associated wiring.

* Valved mains/battery machines did exist but, of the deck, only the pickup was electric, the turntable being spring driven as per wind-up gramophones. These contraptions are, however, outside the remit of this guide.

** The AD28 battery can still be obtained but, as far as is known, nowadays only from online suppliers. It is also rather expensive.
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Old 9th Nov 2011, 1:34 am   #14
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Default Transistorised record players.

This post effectively and conveniently follows on from #13 above.

Valved record players and, as an aside, televisions, survived in production rather longer than valved radios broadly speaking. Transistorised record players (or, more correctly, record players with transistorised amplifiers) became commonplace from the mid 1960's although the earliest examples started to appear rather earlier.

As this post conveniently follows on from the previous post concerning mains/battery machines, we're concerning ourselves only with transistorised amplifiers here.

As with valved record player amplifiers, the transistorised amp' will consist of what, in a radio, would be the Audio and Output stages together with the associated controls and other gubbins such as resistors and capacitors. Other than valves being replaced by germanium or silicon devices, the essential differences between valved and transistorised amplifiers are twofold in respect of the latter:

a) All components run cold (or should do, see later).

b) Voltages are low, typically but not necessarily exclusively, 9V.

Safety warning. On point b) above, remember that if your transistorised amplifier is mains powered, low voltages are only present after the mains PSU (Power Supply unit).

Remember, too, that although the amplifier is low voltage, if the machine is mains powered the deck motor will still be powered directly from the mains supply.

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^ The above image shows the essentials of a transistoried amplifier. As this guide is aimed at the newcomer to vintage record players, in this post we're concentrating only of the fundamentals and areas most likely to give problems.

The image actually shows part of a Roberts radio chassis as this was convenient to photograph. Don't be put off though, for what you see in the image is little different to what you'd see on the amplifier of a transistorised record player. Note that this is a 'transformerless' output stage; an arrangement you may come across in a record player.

Looking at the numbered items on the image, 1 is the audio driver transistor which in this case is an OC75. This is, in a nutshell, a preamp and if on a record player this would be where the signal from the cartridge would enter the amplifier - having first faffed about around the volume and tone (if fitted) controls en route.

At 2 we can see the brass heatsink which, in turn, is clamped to 3, the chassis frame. The heatsink is holding the output transistors, in this case an AC187 and an AC188. Put simply, these transistors are what actually drives the loudspeaker. The heatsink is not there to keep the transistors nice and tidy, it's there to conduct away heat. Like output valves, output transistors run hot - or rather they would do if the heatsink wasn't present.

Even, however, with the heatsink in place and holding the transistors things can - and do - go wrong. To enable the amplifier to do its job properly and for the output transistors to run at a temperature the heatsink can cope with, the biasing must be set accurately. At 4 we can see an adjustable bias resistor; there's actually a pair of these, the second being out of sight in the image, and they're preset at the factory. You must not twiddle or otherwise interfere with these resistors or damage may result to fixed resistors as well as the output transistors. If for any reason the biasing does need a reset, you will need a milliammeter and the service data relevant to your record player in order to deal with it. On some amplifiers even the smallest error in biasing can cause a (fixed) resistor to overheat and for some mysterious reason this seems more common on RBM (Rank Bush Murphy) amplifiers than others. Don't be complacent though, correct biasing is important on any amplifier regardless of brand.

The adjustable biasing resistors are merely circular carbon tracks with a wiper contact, not too unlike the basics of a volume control. They can, therefore, over time, develop poor contact mainly through a build up of muck. If cleaning is thought to be necessary remember, before attempting anything, that you will need a milliammeter and relevant service data to reset them correctly.

Heatsinks and biasing aside, output transistors can develop other faults. On rare occasions a short circuit can occur between one, or both, transistors and the heatsink. When this happens, the amplifier will go totally dead. Sometimes you can trace the fault by removing each transistor in turn from the heatsink, then switching on to see if the amplifier has come back to life. Only do this for a couple of seconds though, just enough time to conduct the test, and do not leave power applied whilst you fiddle with the heatsink.

If this fails, you will next need to grab your meter and service data and then start checking back through the amplifier. If unsure, you're advised to create a forum thread for further assistance. This is not least because amplifier designs can and do vary widely; for example there may or may not be transformers present.

Otherwise, if you're certain the fault lies with the output transistors and the 'removal from heatsink' check fails then it's most probably time to start replacing transistors and "matched pair" then very likely comes into the equation. You are advised to seek additional information on this if you're unsure.

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^ For comparison with the previous image, this one shows a transformer coupled output stage - or rather the essential components of one. The transformer at the rear is the 'driver' transformer (effectively a premap transformer) whilst that at the front is the output transformer. Note how the output transistor heatsinks have utilised the frame of the transformer. This is because in this case there's no metal chassis frame for them to be attached to and thus aid the dissipation of heat. Cheapness in construction, in other words.

This particular arrangement is more usually found in transistorised radio receivers, but it's relevant here as this unit was removed from a Perdiogram 'record player with radio'. More on these in a later post. As well as the possibility of faults and failures with output transistors, the above type of output transformer can be prone to failure. Usually the failure is in the primary (ie input) winding and tends to be more common with mains/battery machines.

So if you have nothing at the loudspeaker and you've eliminated o/p transistor and other possible faults, suspect the transformer. A quick check with a meter will soon confirm; with your meter set on a resistance range, touching the probes on the primary terminals will give a 'click' at the loudspeaker, for example, if both transformer windings are OK. If no 'click' then you'll need to do a continuity check, same method, on both windings but suspect the primary first. If no meter, you can do the 'click' test using a small (no more than 9V) battery and a couple of bits of wire.

The above also applies to transformers of mains (only) machines. In either instance power (to the amplifier) must be off and the position of the volume control is irrelevant. One handy point concerning output transformers is that they're easy to replace; anything of as near as possible the same physical size and which will fit the chassis/PCB or loudspeaker frame in the context of mounting points and wiring/soldering points will usually do the job.

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^ This image, courtesy of Mike Phelan who clambered into his loft to take it, shows a general side-on view of the amplifier of a Bush SRP51 record player. Although not clear (no offence Mike!) it shows the output transistors (the 'output pair'). You can't see them? Well, they're hiding in the gap below the escutcheon beneath the three controls and the chassis itself. These transistors are a matched pair AD161/AD162 and in appearance are unlike most other transistors. The image below of an AD161 will illustrate this.

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^ This image shows extracts from the Bush SRP41 service data; note that's SRP41 and not SRP51 (I have original Bush SRP41 data but not that for the SRP51, hence the cack-handedness).

First looking at the plan on the bottom of the image, the locations of the output transistors are shown - as are the three controls; RV1, RV2 and RV3. This should help clarify the haziness of the earlier SRP51 image, the two machines being practically identical in this respect.

One importance difference, it will be seen, is the use of two identical transistors on the SRP41; both being AD162 types.

Another point worthy of note is that some of these machines have a pilot lamp which also acts as an internal fuse. In other cases, usually on later machines, a 'proper' fuse of the glass type was fitted.

Looking at the top part of the image we see the circuit at the output stage end. We can see the pair of AD162's and the loudspeaker, marked LS1. At this point it's appropriate to mention that SRP stands for Stereophonic Record Player. So, if these machines are stereo, why is there only one loudspeaker? Because for stereo reproduction a matching, add-on, amplifier and loudspeaker unit is required. That for the SRP41 was the AU41 and for the SRP51, the AU51. If you understand circuit diagrams you will see that the output stage is another transformerless example, as mentioned earlier.

We will touch upon stereo machines in a later post, but the Bush SRP types have been deliberately chosen for discussion here because they're a) very common, b) very popular and c) damn good machines - far more so than many (but not all, see a later post) of the rubbish Dansette offerings which people rave over for nostalgia reasons.

The AF117 transistor should be mentioned now. These can appear in, obviously, transistorised record players and especially in the already mentioned 'record player with radio' types where a standard transistor radio chassis was utilised. The AF117 topic and, indeed, any transistor in the AF11x series, has been flogged to death many times in our forums so we're only devoting this one paragraph to it here. To find out all about it see, to give just one example, this thread.

On our main site can be found further information on transistors including testing. However, with regard to AF11x types, testing isn't the usual recourse as experience will teach you that faulty examples are quite readily apparent.
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Old 9th Nov 2011, 1:35 am   #15
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Default Add-on record decks.

From time to time the forums have new members asking about a 'record player' they've obtained. They're puzzled because "no sound comes out of it" and, for that matter, they're puzzled because "it doesn't seem to have a loudspeaker".

Although it's easy to lampoon, the aforementioned statements are understandable given that these 'add-ons' are survivors of a bygone age when people really did have to 'watch the pennies'.

So this post is not exactly concerned with repairs but has been considered worthy of inclusion due to modern-day unfamiliarity with these units. Some advisory notes are included at the end of this post nonetheless. There is a brief mention of add-on units in the attachment here but we'll elaborate with some history in this post.

The purpose of add-on record decks (a term more appropriate than "record player" for the purposes of this post) was to convert a suitable radio receiver into a radiogramophone (radiogram). This may seem pointless in the 21st century but many decades ago it was a case of 'that or go without or make do with the wind-up gramophone'. At one time, in pre credit card, personal loan etc days, only the well-to-do could afford a proper purpose-built radiogram and this situation lingered right up to the availability of cheaper transistorised and, in some cases foreign-made, perhaps light(er) in weight and more compact equipment which didn't take four beefy blokes to shift it. The turning point was perhaps the 1960's when Mr Average, who had a steady job and perhaps had paid off the mortgage, was able to buy one of the then-proliferating mass produced radiograms of the period. Similar machines, albeit basic and somewhat drab in appearance, were around prior to the 1960's of course (discounting the hugely expensive and lumbering beasts of prewar days), but we can take this period as being, loosely, the time when add-on record decks fell out of favour.

So the average working man of 50-60 years ago was lucky enough to own a fairly decent radio receiver but not a purpose built radiogram. so to play the family records which were probably screechy old 78's which often only emerged as a means of getting rid of the in-laws quickly when they turned up on a Sunday afternoon, the wind-up gramophone had to suffice as mentioned earlier. The add-on deck, electric, was an affordable step up which allowed the records to be played through the radio. The radio, of course, will have had a proper volume control (as opposed to stuffing a pair of socks into the gramophone horn - the origin, incidentally, of the expression "Stick a sock in it" and probably a tone control too.

The add-on deck could not be played through just any radio receiver though. Most, but not all, receivers designed for the purpose were for AC mains (only) and had to be provided with sockets, usually located at the rear, for connecting the add-on deck. The radio may or may not have been provided with a 'gram' position on its wavechange switch; if it wasn't you simply tuned to a silent spot on any waveband, put a record on and away you went.

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^ Here are two images of the gram input sockets on the rear of two different radio receivers. On the left can be seen the sockets on a Pye Fenman (Thanks to Mike Phelan for the image). On the right can be seen the sockets on a German Blaupunkt receiver. The use of symbols isn't overly common on British-made receivers; just the initials "PU" (PickUp) or sometimes the word "Gram" being more the usual. Likewise, Aerial and Earth (Aerial Earth, that is, not mains Earth) are more often abbreviated to just A and E. Use of symbols, as per the Blaupunkt, is more common on non British receivers.

Among the earliest, if not the earliest, of these add-on record decks were the products of Messrs J & A Margolin and were marketed under the self-explanatory "Plus-a-Gram" brandname. Do a forum and/or web search for that brandname and you'll find illustrations and other information. These early offerings by Margolin were quite substantial and solid efforts, often in console (floor standing) cabinets and often designed with a flat top to permit a radio receiver of suitable size to sit upon. The ensemble was practical, albeit a little ungainly. We must remember that, back in those days, the radio was given a spot in the lounge and there it stayed as a sort of focal point, so the non portability of these Plus-a-Gram units wasn't an issue.

Not all were console types though, some were designed to be dumped on a sideboard or whatever, with the radio again sitting on its top or beside it according to the choice of the householder. Cabinets, console or otherwise, had storage space for records; almost always in the case of consol types and sometimes in the case of other types. The deck itself could be an autochanger or a single play job, with earlier ones being 78RPM only of course.

J & A Margolin, incidentally, later became much better known by their "Dansette" brandname.

Margolin were not, however, the only ball on the pitch. Other manufacturers produced add-on decks and in due course these became smaller, lighter and, unfortunately, flimsier. These types could, of course, be left in situ with a radio receiver or could be got out and put away again as and when required. The flimsier types could be in a pathetically thin plywood case or, in the worst cases, simply a stiff card case ('vanity case' style) with equally flimsy lid which would warp and defy all attempts to get it to open and close with ease. Philips produced some like this which, when also fitted with their infamous 'rocking' tonearm head, were positively ghastly contraptions once their newness had worn off.

Before I get too carried away knocking Philips we'll move on. Some of the portable add-on units, including later Plus-a-Gram offerings, came in rather sturdier wooden cabinets which resembled picnic set cases when closed. Others, however, came in rexine (or other material) covered sheet metal cases. Perhaps unsurprisingly Philips also did one of those; I once owned one, albeit a Stella branded example (same shop, different facade), but they were by no means the only manufacturer to do so.

This is a convenient point at which the end the brief history and move on to the technical issues.

As will be understood by now, these add-ons consist only of an electric deck and some sort of cabinet. There will be an on/off control or, in the case of single play examples, an on/off control integral with the actual deck and operated by the tonearm.

Potential faults with add-on decks are the same as found on any other deck. However, add-ons which turn up these days have, due to their obsolescence, very likely been stored away out of use for a considerably long time. This could well be for much longer than a 'proper' record player and in less than ideal conditions too.

In these cases the motor will benefit from an overhaul; essentially removal of its bearings, cleaning and relubrication of same and as described elsewhere. What little mechanical linkage there is may also need attention, again as described elsewhere.

The main issue and from the safety angle is the wiring. Internally there will be wiring to/from the motor and any switches which may be present. Check this for corrosion and perished insulation and renew as necessary. Externally there will be the mains flex plus two wires, or a two-core flex, which carries the signal to the gram sockets on the radio receiver. Typically the signal wires terminate with two jack plugs ('Wander' plugs, if you like); one for the 'ground' socket on the radio and the other for the 'pickup' socket. These, their wiring and the mains flex should also be checked and replaced if necessary.

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^ This image (taken from this thread) shows a fairly typical add-on deck and in this instance the cabinet is a relatively sturdy wooden affair. The two cables seen on the left are the mains lead and the lead for connecting to a radio receiver. Note the apparent lack of controls; unfortunately this example is a Stella (Philips in disguise) and Philips/Stella machines are mentioned in more detail in the next post.

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^ Close up of a Philips add-on deck showing the wanderplugs for connecting to a suitable radio receiver. The red plug has been removed to show more clearly the coaxial (screened) lead used to connect deck to receiver. The black plug connects to the outer part of the lead, ie the screening which links to the 'ground' side of the cartridge, whilst the red plug connects to the inner core of the lead and carries the signal from the cartridge. The screening also, at least in theory, prevents the lead from acting as an aerial and superimposing unwanted interference onto the audio from the record.
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Old 9th Nov 2011, 1:41 am   #16
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Default Philips (Non auto).

As stated way back at the beginning, we're adhering to the common types and brands of record player. The vast majority of those will be fitted with decks by BSR, Garrard and Collaro. Unfortunately Philips machines from the 1950's/60's still turn up frequently and these contraptions are a law unto themselves.

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^ This image appears elsewhere but it's convenient to repeat it here. What we can see is the usual cause of trouble with Philips machines of the relevant era; the 'rocking' combined headshell and cartridge. This particular headshell is an AG3016 but there were several versions with, of course, differing part numbers. Another version is seen fitted to the Stella contraption in the previous post. Incidentally, if the Philips/Stella thing is confusing then we'll explain. Philips and Stella were essentially the same, the difference being that Philips badged items were sold only via appointed Philips dealers and Stella badged items could, for all intents and purposes, be sold via any Tom, Dick or Harry. This was not unusual, HMV and Marconiphone being the same (HMV - appointed dealers, Marconiphone - Tom, Dick or Harry).

The underside view, above right, shows the two adjacent styli and the entire head can be turned through, I don't know, some 20 or 30 degrees to enable selection of either stylus. Of the 'M N' markings on the top; 'M' is for the Microgroove stylus (in other words, vinyl records) whereas 'N' is for 'Normal'. The latter means 78RPM records, these still being the standard (hence, Normal) type of record at that time.

So if the Philips headshell/cartridge fails - which it will do if it hasn't done so already, what do you do? As said elsewhere, replacements can just about still be purchased but they're expensive and differ somewhat in external appearance. These replacements are also fixed, ie they no longer use the 'rocking' feature, and a conventional flipover stylus is used. An alternative is to gut the old headshell and fit a conventional cartridge. This operation is fiddly, often messy and requires some adaption, whilst only a very few conventional cartridges are small enough to fit. Ask in the forums if you find yourself facing this predicament.

If, however, you have one of these rocking heads which is still in good order and need new styli then styli are still obtainable. Check our Suppliers sticky in the Vintage Audio section. See also post #17 below and the warning therein.

Moving on now, we'll mention the various types of Philips record player from the era concerned. Essentially there were two; the add-on effort seen in the previous post and the 'Disc Jockey' range.

Several variants of the Disc Jockey were produced, the vast majority used the odd headshell/cartridge arrangement already described but a very small few were made with a more conventional tonearm arrangement. Most Disc Jockeys which turn up have the loudspeaker mounted in the lid, protected externally by an expanded metal grille and internally by sturdy wire mesh. The idea was this; the operator (the disc jockey, if you like) would play records with the lid up and thus with the loudspeaker facing the room full of bopping teenagers.

Philips operating instructions stated the following:
Quote:
The lid is detachable and the instrument may be played with the lid on or off. The quality is best with the lid off and placed across the corner of the room.
To facilitate this (dubiously desirable) feature, which is probably responsible for so many of the pesky things surviving today, a lengthy 'speaker lead was fitted. In some instances this connected to the amplifier via two 'Wander' plugs which fitted into sockets on the deck plinth. These plugs/sockets can give problems; poor plug-to-socket connections due to dirt and/or wear and poor connections between 'speaker wire(s) and plug(s). In other instances the 'speaker wire disappeared beneath the plinth (the wooden board the deck mounts upon) to be connected directly to the amplifier.

The loudspeaker arrangement, as might be expected with Philips, has its problems. With the lid shut the loudpeaker is horizontal and, because it's designed to operate in the vertical plane, can suffer from less-than-acceptable frequency response. On the other hand, with the lid open and/or detached, anyone in close proximity to the deck can hear the mechanically produced acoustics from the stylus. Of course, you can turn up the volume to drown this out but then you might have a problem with the lid vibrating and, if it's been moved from the deck and placed on a table, sideboard or whatever, may gradually creep and end up crashing to the floor.

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^ This is in fact the same deck as appeared towards the bottom of the previous post but with the lead moved out of the way. It's convenient to reuse the image as that very same deck was also used on Philips/Stella single play record players (that is, self contained with amplifier and loudspeaker as opposed to add-on). Incidentally, the should be a Philips badge on this deck, mounted just above the turntable, but it's absent on this example.

Towards the top of the image we can see the speed change lever, awkwardly located beneath the tonearm and close to the rear of the cabinet. These levers do not have a very positive feel to them when in use, mainly because they operate via a number of springs. Any problems here and you should suspect springs (broken, detached, missing or stretched) and/or other parts of the linkage which may have seized due to the familiar lubrication issues.

At the base (the dome shaped part) of the tonearm we can see another control (The "Auto Stop Lever") with an operating lever and, diametrically opposite, a pointer and scale (the latter is none too clear on the image. These decks are designed to shut down when the tonearm has reached the end of a record and the control in question is used to set the point of shut down. It can be very fiddly to set up so as to work correctly and thus is one of the common 'fault assumptions', shall we say, with these decks. Philips operating instructions state the following:
Quote:
This adjustment makes it possible to set the player to accommodate all standard sizes of record. This lever should be turned in a fully clockwise direction before attempting any adjustment. The record which it is desired to play should be placed on the turntable and the motor should be started by gently swinging the pick-up arm back away from the turntable. The pick-up arm should then be held over the beginning of the run-off groove of the record and the auto stop lever turned in an anti-clockwise direction until the motor stops. The adjustment is now correct for this record. By noting the position of the pointer against the marking, this adjustment can be pre-set for other records.
Why Philips thought this rigmarole was necessary is a mystery, especially when considering other manufacturers fitted auto shut-off to their single-play decks which required the operator to do - nothing. So if you can get this feature to work properly, and repeatedly so, then well done. Otherwise there'll be problems with worn and/or damaged linkages which can be awkward to sort out; create a forum thread giving details and images if you find yourself in this position.

Caution: The linkage for the motor start and auto shut-off features operates, obviously, a mains switch located below the deck. You are therefore advised to ensure the machine is disconnected from the mains supply before attempting repairs or adjustments to the below-deck mechanism.
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Old 25th Nov 2011, 10:24 pm   #17
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Default Philips (autochanger types).

Unfortunately I don't know everything, far from it, and this particular post has proved problematic. My knowledge of autochanger Philips machines from the Disc Jockey era is one such grey area and, despite asking for assistance in the forum, nobody offered to help. I'm therefore limited to providing a couple of links, as per below, which will hopefully be of help:

https://www.vintage-radio.net/forum/...ps+disc+jockey

https://www.vintage-radio.net/forum/...ps+disc+jockey

Other information is likely to be found via forum and web searches as well as from service data, when/if available.

There are nonetheless a few points I can add. That now-troublesome rocking pickup head was also common on autochanger machines. If these need rebuilding or replacing with the still (at the time of writing) available substitute, the autochanger tonearm does, or usually does, have provision for tracking weight adjustment.

Beware
. The replacement head mentioned is, usually, the GP235 which at the time of writing has become ridiculously expensive (50 new, give or take, but shop around). Therein lies the main drawback with obtaining these machines; my own advice to anyone tempted to purchase one is to first check that the cartridge is still good before purchasing if at all possible. Whilst accepting that safety considerations are paramount with old electrical equipment, if the vendor of a Disc Jockey says "Nah mate, can't plug that in - it's sold as seen" then either steer clear or be prepared to pay repair/replacement parts bills totalling a lot more than you've probably paid for the record player. This of course applies to any Philips machine, be it auto, single play or add-on, which uses that pesky 'rocking' pickup head.

Idler wheels were, perhaps not surprisingly, peculiar to Philips are are now virtually impossible to replace. So if your tempted to obtain one of these machines then be wise and attempt to ascertain it's working condition first; a disappointment here is better than a lot of hassle later having purchased the machine blind.

Fortunately, once out of the Disc Jockey era Philips produced somewhat more conventional offerings and problems with these are broadly relevant to other posts in this thread.
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Old 13th Apr 2012, 5:23 pm   #18
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Default His Master's Voice (HMV).

As per the last paragraph of the previous post, general problems with HMV machines can be covered by other posts in this thread.

However, one area which should be highlighted concerns earlier machines which used the EMI 'Double C' pickup head/cartridge. These are notoriously difficult to replace although repairs are apparently possible.

The following two threads will give an idea:

https://www.vintage-radio.net/forum/...t=hmv+double+c

https://www.vintage-radio.net/forum/...ad.php?t=40489

As with the previously mentioned Philips autochanger machines, you're advised to be very careful if tempted to purchase one of these HMV efforts. It is unfortunate, albeit understandable, when people are unwittingly tempted to purchase what they see simply as a record player without being aware of the potential problems.

As, again, with Philips, HMV and Marconiphone machines became more conventional once they got over the fad for these odd 'Double C' contraptions so don't let comments herein discourage you from purchasing all HMV machines (a common purchase nowadays are the transistorised stereogram machines from the 60s and 70s).
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Old 13th Apr 2012, 6:00 pm   #19
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Default Stereophonic and multiple 'speaker machines, general information.

As stated way back at the beginning of this thread, stereophonic (hereinafter "stereo") machines are excluded for the following reasons:

a) They are not the typical machines which newcomers seek help with; "typical" being the crude, mono, efforts from the likes of Dansette, Fidelity, E.A.R and so forth.

b) The typical, cruder, machines mentioned above are usually repairable by newcomers/beginners with little initial relevant knowledge, by means of guidance of forum members and, we hope, threads such as this one. Stereo machines are usually far more complex and thus often beyond the understanding of the beginner. Of course, everyone can learn so such comments are not intended to be patronising.

To expand upon point b) above, stereo machines vary greatly in layout and complexity; take as an example the comparison between a Pye 1005 (look that one up) and, say, a Bush SRP-whatever with its add-on amplifer unit. These variations therefore make detailed explanations herein rather impractical for the beginner, so searching the forum and/or creating a new and dedicated thread for your particular stereo machine would be a better idea.

However, despite wishing to avoid the subject herein it would be unfair and unhelpful to omit giving a basic understanding of what stereo is and how it works so off we go:

Records, cartridges and styli

Confusion, or simply lack of knowledge, concerning mono/stereo records and mono/stereo/stereo compliant cartridges and styli is common. Therefore although touched upon elsewhere it's not a bad idea to elaborate here.

A mono record has tracks giving only lateral (side to side) oscillations. Stereo records have tracks giving both lateral (Channel 1) and vertical oscillations (Channel 2). A mono cartridge therefore needs to handle only a single channel and therefore has only two terminals on its rear. A stereo cartridge is therefore in effect two cartridges in one, hence it will have four terminals on its rear (two per channel or, in the case of an odd few, three terminals: Channel 1 - Common ground - Channel 2). Note that the two channels are usually marked on the rear of the cartridge together with the respective 'signal' and 'ground' terminals, but you need a magnifying glass to see them.

Take note of the wiring colours too before you disconnect a cartridge, or you'll be in a muddle later on. Of the four wires, one will be lefthand signal, another righthand signal, another lefthand ground and the remaining wire righthand ground. For reference the common setup is:

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Blue - Left channel ground.
Red - Right channel signal
Green - Right channel ground.

A fifth, usually black, wire may also be lurking and this is merely an earth connection from tonearm to chassis.

Styli, as will by now be realised, are designed to handle a single channel if mono but two if stereo; the mono stylus moves only in one plane (lateral) but the stereo stylus moves in both planes (lateral and vertical). It is for this reason that you should not attempt to play stereo records with a mono stylus due to the "non compliance" of the latter.

However, some mono record players may be fitted with a mono but stereo compliant cartridge and stylus, meaning stereo records can be played albeit with only mono reproduction.

Multiple loudspeaker (non stereo) machines

A common misconception is that a record player (or, for that matter, a radio receiver) with more than one loudspeaker is stereo but this is not necessarily the case. Quite common are machines with multiple loudspeakers simply wired in parallel, but otherwise are essentially straightforward mono machines. The kindest thing you could say about these is that they give 'pseudo stereo'.

Stereo machines, self contained and adaptable

Back in post #10 we gave a simple explanation of the Push-Pull amplifier but to very quickly recap this type of amplifier will have twin output valves (or transistors), each of which amplifies one phase of the audio signal to ultimately give greater output at the loudspeaker(s) at any given volume control setting.

In a stereo machine the above is in effect duplicated. A little earlier we described how a stereo cartridge could be described as two cartridges in one, with four (sometimes three) wires leading from the cartridge instead of the two found with mono. Put in very simple terms, this situation continues through the stereo machine, via the single premap stage, to the phase splitter and output stages to the loudspeakers. However, it isn't quite that straightforward as a Balance control will be in the circuit and biasing has to be set accurately to prevent distortion and possible damage.

The 'self-contained' stereo machine has everything in one cabinet, although we can include machines with seperate 'speakers in this category (1970s 'Music Centres' for example). Some machines may contain a mere two loudspeakers, others may contain as many as six. An example of the latter is the Pye 1005 (Achoic) and it's variations. It will now be realised that circuit complexity varies widely, hence the reason it is not practical to provide an in-depth repair guide to stereo machines in this guide.

'Adaptable' stereo machines include those which are, on their own, essentially mono but cosmetically and electronically matching add-on amp/speaker units to convert them into stereo were available. Very common among these are the Bush SRP units, mentioned in this guide and widely in the forum, and others were produced by Hacker, Dansette and a few more. The add-on units are relatively scarce but see this thread for an interesting and rare Dansette example.

Stereo adaptable machines, by nature, have differing circuitry again. It's worth repeating here about heatsinks in transistorised examples. To prevent overheating and failure of output transistors, the latter must be run attached to their heatsinks (which may take the simple form of the chassis itself). Common output transistors are the large AD161/2 types, of which there'll be four in a true stereo machine. These are usually found bolted by their flanges to an alloy component forming part of the chassis and acting as the heatsink. Do not attempt to run the machine with any output transistors disconnected from the heatsink (see next paragraph for the exception). If you do, overheating and failure will result.

A further problem with output transistors is the possibility of short circuits through the transistor case to the heatsink. This is not unknown with the AD161/2 types and indeed can occur with any output stage transistor - not just in stereo machines although it seems to happen more often in the latter. If this is suspected it is permissible to check by briefly disconnecting the transistor(s) from the heatsink to see if operation is restored. Do not do this for anymore than a few seconds though.

That's about all that is felt practical to include in this guide about stereo machines. Once again, if necessary you will find various threads concerning various stereo machines in the forum. Otherwise please create a new thread giving details of your machine and the problem(s) you're encountering.
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Old 18th Apr 2012, 8:07 pm   #20
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Default Miscellaneous bits and pieces.

So your newly acquired record player with one careful previous owner (but two dozen more careless owners) has a turntable which rotates the wrong way, explodes midway through a record or stubbornly refuses to play whenever you load a Cilla Black record. All these things can be put right but it's the small niggles which can cause the biggest headaches:

Control knobs

As with radio receivers, missing or damaged knobs can also be a problem on record players and this also applies to rotary-type deck controls (Collaro speedchange knobs, for example, have a habit of going missing).

Obviously these cannot be obtained new, so your only options are to place a request in our Sets & Parts Wanted (S&PW) section with a picture of the knob type you require if at all possible, or replace with non original types.

It's worth remembering that some knobs, specifically on/off, volume and tone may well be identical, or very similar, to the knobs used on the manufacturers radio receivers from the same period.

Turntable mats

These are now becoming a serious problem when replacement is necessary. With age and, perhaps more to the point unsuitable storage conditions, these mats perish and eventually crumble away.

You might be lucky as a result of a request in S&PW but improvisation is often the only recourse. Do a forum search, keywords "Turntable mat" or "Platter mat" for more information.

Lid hinges, catches etc.

Record players seldom turn up minus their hinges and catches, but they frequently turn up with these items damaged and/or badly corroded.

If replacements are needed then, again, ask in our S&PW section. However, the majority of these items are of Cheney manufacturer and a web search using that name as the keyword will show several suppliers, one such being Sid Chaplin who is a Godsend for items like cloth, handles and cabinet fittings.

Bear in mind that carrying handles, as fitted to portable record players, invariably have plated, or sometimes anodised, end caps to match the other cabinet fittings.
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