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Old 17th May 2017, 7:22 pm   #21
Edward Huggins
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Default Re: Dansette Major Deluxe

The amp will not need replacing, but repairing.

These are very simple to work on, but if you have no previous experience it may be that a Member from this Forum can help you out. It all depends on what you feel you can (safely) take on. If needed, you can post a Message for help via this Forum.

Bear in mind the amp may need repair and at this stage you might also need some form of (near equivalent) cartridge. You also need to consider what type of records (whether stereo, mono or both) you want to play on this.
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Old 18th May 2017, 10:16 am   #22
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Default Re: Dansette Major Deluxe

Quote:
Originally Posted by Station X View Post
Do the valve or valves light up? Is there any background sound at all from the speaker?
There is a constant drone not loud and not affected if you turn the volume and the valve does light up. A few years ago I sent the chassis to a place that did repairs and they fitted some more up to date parts and it was working when it came back but has stood for a few years again unused.
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Old 18th May 2017, 10:49 am   #23
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Default Re: Dansette Major Deluxe

"Constant drone" sounds like mains hum to me and would be down to faulty smoothing capacitors.

Your posts suggest that you have little experience of repairing record players. If you want to repair the player yourself you'll get plenty of good advice on here. On the other hand you may wish to use the services of a repairer.
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Old 18th May 2017, 11:23 am   #24
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Default Re: Dansette Major Deluxe

That was what was wrong with mine. It uses a purpose made electrolytic with 3 capacitors in a small can so the only realistic option is to remove it and replace with separate capacitors. If I remember correctly, the can has multiple solder tabs to the board which form part of the circuit.
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Old 18th May 2017, 12:52 pm   #25
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Default Re: Dansette Major Deluxe

In the past, as I've mentioned on the forum before, I've used a modern dual can electrolytic of the appropriate value for the reservoir and smoothing capacitors. The third cap. in the original can is the EL84s cathode bypass capacitor, which can be replaced with a modern, preferably axial leaded, 22 or 47uf 25 volt electrolytic.
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Old 21st May 2017, 12:46 pm   #26
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Default Re: Dansette Major Deluxe

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Originally Posted by 'LIVEWIRE?' View Post
In the past, as I've mentioned on the forum before, I've used a modern dual can electrolytic of the appropriate value for the reservoir and smoothing capacitors. The third cap. in the original can is the EL84s cathode bypass capacitor, which can be replaced with a modern, preferably axial leaded, 22 or 47uf 25 volt electrolytic.
Thanks for that but it is a bit over my head I am afraid. I am starting to think it may be better to find someone who I can send the chassis to and they can repair it for me. Don't really want to send the whole player.
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Old 21st May 2017, 1:03 pm   #27
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Default Re: Dansette Major Deluxe

I can fix this for you if you don't find anyone nearer. I'd only charge for parts.

PM me if interested.
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Old 22nd May 2017, 5:30 pm   #28
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Default Re: Dansette Major Deluxe

Sounds good to me if you are willing to send address i will strip out chassis and send it to you.would be very grateful.

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Old 23rd May 2017, 9:48 am   #29
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Default Re: Dansette Major Deluxe

You have a PM.
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Old 2nd Jun 2017, 10:59 pm   #30
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Default Re: Dansette Major Deluxe

The OP sent the player's amplifier to me and this afternoon I found time to work on it.

VISUAL INSPECTION

The amplifier is type MC/1961/ ie a minimalist amplifier!

The original metal rectifier was still in place.

The EL84 valve had been replaced with a Russian 6P14P.

All the capacitors had been changed.

The mains transformer has bubbled out wax at some time.

The output tags on the mains switch had been bent and were touching each other. This would have put a full short across the mains supply. As the amplifier had been previously working after a fashion, I assumed that this had happened when the amplifier was removed from the player. I carefully bent the tags back into position.

Where the wires to the speaker were soldered to the output transformer a strand of wire appeared to be bridging the terminals. (Sorry about the poor picture). The soldering and possibly the wires obviously aren't original. I snipped off the offending strand and a few others.

The input wires from the cartridge were unscreened and about six inches long. I guessed this would be a source of hum pickup, so I grounded the "hot" input wire to the chassis.

TESTING

As the mains transformer had overheated at some time, I wondered if there was a short across the HT supply. I applied my capacitor reformer to the smoothing caps and the current rapidly fell to zero, showing all was well. The caps held their charge for several minutes.

I connected the speaker and the mains lead using chocolate block connectors. I also fitted a chocolate block connecter to the wires which fed the turntable to prevent them shorting, or my touching them and getting a nasty shock. On switching on at the wall socket the first thing I discovered was that the player's OFF/ON Switch remained ON regardless of the position of the control. It needs repairing or replacing.

With the valve not fitted the HT measured 370 VDC. I quickly switched off as one of the smoothers is only rated at 350 VDC. With the valve fitted the HT fell to 207 VDC. The cathode voltage was 3.85 VDC indicating a combined anode and screen current of 38.5mA.

The loudspeaker was silent apart from some rustling when the volume and tone controls were operated. I gave them a squirt of Servisol which cured this. On ungrounding the "hot" input wire a gentle hum was heard in the speaker. Holding this wire resulted in a loud hum from the speaker, which was as expected.

I connected an audio generator to the input and was able to hear good audio from the speaker up to 11kHz at which point my hearing ran out.

I substituted the speaker with a dummy load/AF Wattmeter. My understanding is that the BSR TC8H cartridge used with this player has an output of 4 VRMS, so I set the audio generator's output at that level. The audio output at 1kHz was 1.15W, falling to half that at 20kHz.

I decided to try the effect of increasing the HT, which I did by soldering a silicon diode across the metal rectifier. The HT without the valve was 380 VDC and with the valve inserted 224 VDC. Cathode voltage was 4.42V indicating a combined anode and screen current of 44.2mA. Audio output was 1.3W. Increasing the HT hardly seemed worthwhile, so I removed the diode.

During testing the mains transformer got hot, but not too hot to touch.

I'll put the valve on the CT 160 tomorrow and run an extended soak test. Maybe find a source of music to apply to the input.

CARTRIDGE

I connected the cartridge to the amp's input and stroked the stylus. Scratching was heard from the speaker. Whether the cartridge's output is good enough I can't tell, as I don't have a player to try it in.
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Last edited by Station X; 3rd Jun 2017 at 1:00 pm. Reason: Picture added.
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Old 3rd Jun 2017, 9:50 am   #31
Edward Huggins
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Default Re: Dansette Major Deluxe

I enjoyed Graham's step-by-step report on this. That simple amp needed quite serious attention. We do not as yet know how good the cartridge is other that it may still be the original Mono only type. If it's a BSR TC8H (orange body) and does work, all will be well to at least use it for Mono LPs. It will be near impossible to source a stereo-compatible equivalent.
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Old 3rd Jun 2017, 1:22 pm   #32
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Default Re: Dansette Major Deluxe

UPDATE.

The 6P14P (EL84 equivalent) tested good on the AVO CT160 Valve Tester.

I ran the amp flat out into the dummy load/wattmeter for an hour. Output stayed constant at just over a watt. The mains transformer got hot, but not excessively so.

I then reconnected the speaker to the amp and fed audio from an FM Tuner into it. The audio quality was what I'd expect from a simple Dansette amplifier. The volume and tone controls worked and the mains transformer didn't overheat. It's been running like that for two hours now.

The cartridge is a Ful Fi TC8H coloured white. Its pins were tarnished black so I cleaned them. The cartridge has some output, but in the absence of a player it's impossible to tell whether it's able to drive the amplifier at a sufficient level.

CONCLUSIONS

With the possible exception of the wire strand shorting the speaker I don't think there was anything preventing the amplifier from working. I'll fit new speaker wires and make sure they don't short.

If the OP wants me to I'll replace the volume control and ganged mains switch, assuming I can source one.

I'm not sure whether the wires from the tag strip under the deck to the amplifier should be screened, or perhaps a twisted pair. Perhaps someone with a similar player can advise? I can fit a screened lead if need be.
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Old 3rd Jun 2017, 1:45 pm   #33
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Default Re: Dansette Major Deluxe

Often the wires to the amp on these were just a twisted pair. If it's a TC8H cartridge, and it's white, that's unusual.
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Old 3rd Jun 2017, 2:21 pm   #34
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Default Re: Dansette Major Deluxe

Definitely a TC8H and it's definitely white now!
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Old 3rd Jun 2017, 5:14 pm   #35
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Default Re: Dansette Major Deluxe

Maybe white with age?! There was a Japanese clone of the TC8H made in Black.
My only other option is that there was a rare version of the orange bodied BSR TC8H (1.0V) which gave even more voltage output at 1.2V. Maybe that was white? The TC8S Stereo cartridge was definately white. The voltage outputs are as quoted from my BSR Dealer Newsletters of 1958/9 using BSR's measurement crtieria using cms per sec.
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Old 4th Jun 2017, 9:25 pm   #36
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Default Re: Dansette Major Deluxe

Figuring that I had nothing to lose I decided to have a go at fixing the stuck mains OFF/ON switch. It was making a nice click when the volume control was rotated, but the contacts remained stubbornly made.

I CAREFULLY bent back two of the three tabs holding the switch assembly to the volume control potentiometer. Before separating it from the pot I covered it with a piece of rag to catch any flying springs and other parts. This proved unnecessary though.

A lug attached to the rotating part of the volume control engages in the "V" shaped piece of metal in the switch toggling the spring loaded pin and moving the paxolin? "yoke" to which the contacts are attached.

The pin was toggling all right, but wasn't taking the yoke with it. I moved the yoke with a small screwdriver expecting to find burned or welded contacts, but they were in perfect order. Moving the "V" now toggled the yoke correctly and a check with a DMM showed that the contacts were making and breaking correctly.

Before reassembly I applied some silicone grease to the area of the casing's back plate which the yoke moves over. Before bending the tabs back to their original position I tested the switch again several times to confirm correct operation. I don't think the tabs will stand bending more than once.

The picture shows the switch in the OFF position after freeing off.

The amp now has new speaker leads and this afternoon I listened to "Pygmalion" on it. Tomorrow it will be on its way back to the OP.
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Old 4th Jul 2017, 2:38 pm   #37
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Default Re: Dansette Major Deluxe

I have taken the deck away all together and disconnected all wires but the drone still there.It gets worse when you increase the volume and also when you get hold of the red wire from the switch.could this be a bad switch.
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Old 4th Jul 2017, 2:44 pm   #38
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Default Re: Dansette Major Deluxe

Welcome back. Do you mean Hum when you say "Drone"? If you are holding the bare end of the red wire to the volume control, you will get a Hum which should go away when you leave it alone.
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Old 4th Jul 2017, 2:46 pm   #39
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Default Re: Dansette Major Deluxe

It is not when you hold bare end you just have to get hold of the wire.
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Old 4th Jul 2017, 3:24 pm   #40
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Default Re: Dansette Major Deluxe

You have an open circuit grid connected to that wire, breathing on it will result in 50Hz hum pickup by induction never mind the bare end.
If you ground that wire preferably with a capacitor, around 10nf, not critical, it should kill the inductive pickup. Any hum then is from the mains.
Bad smoothing caps, heater to cathode valve leaks, shot decoupling caps, heater wiring close to the input grid wiring etc will all give hum to some degree.
These simple cheap amps always hummed a bit.
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