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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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23rd Aug 2017, 6:50 am | #21 |
Octode
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
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Re: Connoisseur two speed turntable 1950?
47K is just the load resistance needed. most modern cartridges have between 400 and 700 ohms resistance.
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23rd Aug 2017, 9:18 am | #22 |
Hexode
Join Date: Jan 2006
Location: Greater Manchester, UK.
Posts: 373
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Re: Connoisseur two speed turntable 1950?
Do they well I never knew that, you learn something new everyday.
So then it should work just fine apart from the high output, which should overload the input stage I would assume that 15mV is a bit rich for most phono inputs? Or then my assumption that there is a break in connection or a lead somewhere between the cartridge slide on head block and the end of the leads? Simplest solution I suppose either assume they are dud and replace them or measure the leads and then replace them anyhow? |
23rd Aug 2017, 9:24 am | #23 |
Hexode
Join Date: Jan 2006
Location: Greater Manchester, UK.
Posts: 373
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Re: Connoisseur two speed turntable 1950?
Well I may have missed that you mentioned the head was open circuit. Pity I have no idea if mine are open circuit or not, I am pretty sure I have a red & green. I defo have a microgroove in the original presentation box.
The box is very well made with really high quality catch on the front and what looks like the real version of rexine in some no doubt now endangered species. Connoisseur is embossed into the leather, I think some of them even have their styli, not sure that there is much difference between the red/green and microgroove there are but mostly around the stylus/shank area. The problem even if we can find one that works will be the stylus bound to be worn out, where and how much would it cost to get it replaced? Oh yes I think there was a yellow as well but my memory could be playing tricks with me. |
24th Aug 2017, 4:09 am | #24 |
Tetrode
Join Date: Mar 2010
Location: Tauranga, New Zealand
Posts: 61
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Re: Connoisseur two speed turntable 1950?
Restoration notes
The motor rubber mounts had disintegrated.I made some from some thick rubber, and used Ados F2 to glue. The dimension surface to surface is now 0.9 cm close to 3/8 '' The motor was 'no go'. Traced to a burnt out wire in a connecting sleeve between two of the coils.A 220 ohm resistor in another sleeve on top of the speed change switch also burnt out.The 4 coils all tested OK. There is a 0.001 500v capacitor in series with the resistor.The cap and resistor were replaced. The motor now ran but was 'noisy'.I dismantled cleaned and lubed the bearings.There wasn't a ball in the tapered base of the lower bronze bearing for the rotor shaft:i didn't know if it should have one or not, so put in the ball from a Biro in case. The motor still ran rough,so i suspected the phase cap. sealed in a tin box. Took this apart and found a 0.47uf 1000v cap which measured nowhere near this.I tried a few different values of replacement, and found 0.3gave very quiet running but insufficient torque to start the turntable.Values of 0.47 and higher caused increasing motor vibration.I settled on 0.4. |
24th Aug 2017, 6:12 am | #25 |
Octode
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
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Re: Connoisseur two speed turntable 1950?
Bottom diagram looks wrong shorting out one set of coils?
Last edited by peter_sol; 24th Aug 2017 at 6:17 am. |
24th Aug 2017, 7:16 am | #26 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
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Re: Connoisseur two speed turntable 1950?
I thought that he was A R Sugden, with the A for Arnold
He was certainly forward thinking and connoisseur equipment was rather good, too. A friend and neighbour in Almondbury had a BD1 turntable and a pair of Connoisseur omnidirectional column speakers. Gilbert Briggs Arnold Sugden J E Sugden 'Richard Allen' Fane RSC Matt Mathias Forget rhubarb, there was a Yorkshire audio triangle David
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24th Aug 2017, 9:25 am | #27 |
Hexode
Join Date: Jan 2006
Location: Greater Manchester, UK.
Posts: 373
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Re: Connoisseur two speed turntable 1950?
Did I say Arthur I meant Arnold, did I get him confused with Haddy was his name not Arthur?
Without looking back over what I said I seem to recall that I said Arthur no idea why other than it was the wee small hours of the morning. |
24th Aug 2017, 6:46 pm | #28 |
Heptode
Join Date: Jan 2006
Location: Todmorden, West Yorkshire, UK.
Posts: 870
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Re: Connoisseur two speed turntable 1950?
Here's a picture of a Mark II "superlightweight" arm and 78rpm cartridge, slightly different from Tim's.
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25th Aug 2017, 3:49 am | #29 |
Tetrode
Join Date: Mar 2010
Location: Tauranga, New Zealand
Posts: 61
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Re: Connoisseur two speed turntable 1950?
Peter Sol, yes, i did make a mistake with the 78 wiring diagram.Amended one attached. I double checked with the multimeter, so if it's still puzzling perhaps someone can analyse it for us.
Just to be clear, the arm on the TT has nothing to do with Sugden,but does have good bearings so pressed into temporary service with the GE cartridge. Have included some photos of Sugden's arm,- had to make a counterweight as the original missing. Also a dismantled head.The stylus looks fairly easily replaceable once the brass plate is unscrewed.The stylus rod is pushed? through a piece of wood held in the body by thin pieces of rubber each end. The magnet is cylindrical transverse in the body with pole pieces in contact each side. I replaced the original unshielded pair of wires with shielded cable. |
25th Aug 2017, 5:04 am | #30 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
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Re: Connoisseur two speed turntable 1950?
Are you sure the connections don't cross over in the middle of the diagram when 78rpm is selected -- that is that the top of the right hand coil is connected to the end of the capacitor on the left hand coil? That would reverse the motor in 78 rpm mode, which has been suggested before.
It's possible that is done via a switch contact that has got dirty and thus is not showing continuity after all these years. |
25th Aug 2017, 6:20 am | #31 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
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Re: Connoisseur two speed turntable 1950?
The usual way to reverse a split-phase induction motor (which this looks like) is to have the phase-shift capacitor permanently connected between the live ends of the two windings, and apply the live mains to one or the other end of it using a SPCO switch. So one winding always gets mains directly, while the other gets it phase-shifted by the capacitor; and which is which determines the direction of rotation.
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25th Aug 2017, 6:58 am | #32 |
Tetrode
Join Date: Mar 2010
Location: Tauranga, New Zealand
Posts: 61
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Re: Connoisseur two speed turntable 1950?
Tony and Julie, yes you are correct, and yes the switch contacts were making poor contact. so there is a crossover, yellow connects to orange as well as black to green.
Thanks both for your input. |
25th Aug 2017, 9:35 am | #33 | |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
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Re: Connoisseur two speed turntable 1950?
Quote:
Martin
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26th Aug 2017, 11:46 pm | #34 |
Tetrode
Join Date: Mar 2010
Location: Tauranga, New Zealand
Posts: 61
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Re: Connoisseur two speed turntable 1950?
Thought i'd better add the correct motor circuit for completion. Sorry about the previous errors, (no elder abuse please!)
Now a warning for anyone dismantling one of the 'red' or 'green' heads;the rubber strips holding the stylus wood mount harden or go sticky with age and the fine wires from the coil run underneath, and are likely to stick to the rubber, so be careful in prising the bar out. |
7th Sep 2017, 4:37 am | #35 |
Tetrode
Join Date: Mar 2010
Location: Tauranga, New Zealand
Posts: 61
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Re: Connoisseur two speed turntable 1950?
Final Turntable tuning.
Replacement 78 rpm idler arrived from 'barreter' (many thanks), was cleaned lubed and installed. But it wasn't going to be that easy.The centre portion of the 78 idler is quite 'tall',- it's where you can add a drop of oil,- and it was touching the underside of the platter. This meant that the motor suspension rubbers i'd made were too long. Out came the motor again, and slightly shorter ones glued in. This is easier to do if the top cover is taken off the motor and rubbers glued to one surface, then when cured, glued to the other surface. The rubber used can't be too compliant, as the pressure of an idler against the rim puts sideways pressure on the rubbers. The idlers were now correctly positioned and their mounting plate had to be adjusted for correct pressure against the platter rims. This is critical, too much and the TT runs slow and as both idlers are on the plate getting a setting that is correct for both is fiddly. Microgroove head. This had an 'open' coil and the stylus jewel was missing.I dismantled the head and unwound the coil, or tried to, very fine wire that breaks easily. Took it all off,- the break was at the inner part under some glue- didn't attempt a rewind with this wire, but used some from an old electromagnetic speaker field coil.Put as much as i could fit on the bobbin, but even then the DC resistance was only 3.5 ohm. I epoxied a diamond, and a tiny bit of bit of it's shaft, cut from another stylus into place. Reassembled the cartridge and fed it through a moving coil head amp. Surprise! plenty of output, and sounded as least as good as the GE cartridge i was using. One reason why some of these cartridges have poor or no output might be due to the coil wires only being clamped under the contact prongs and prone to oxidation/corrosion. |