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  #1  
Old 05-04-2014, 09:44 PM
omegaman omegaman is offline
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1960 Telefunken Stereo changer

I salvaged this from an unfortunate Telefunken Dominante console. It is a TW-501 changer.

The changer had been in my garage shed for a couple of years and when cleaning it out got the Telefunken changer out, deciding to try to get it working.

After scrubbing the green platter mat with comet I used spray adhesive to remount the patter mat, taking care to get it centered.

I mounted some MCM legs on it so I can observe the action

I pulled the changer apart and re-lubed it nice. The idler wheel responded pretty good to some re-grip treatment but it is cracked and is noisy so I ordered one from Gary at VoM

It no longer stalls and cycles pretty good.

Heres the thing:
It has a Sonotone 8T cartridge.
It is a ceramic cartridge but plugging it into a line-level input sounded weak and wrong, but plugging this Sonotone 8T cart and stylus into the mag phono input sounds good and correct, except for the rumble of the idle wheel. So reading up on the Sonotone 8T it said that the later 8T's has output matching magnetic cartridge outputs


I have the manual from uhhh downloaded

Does anyone have experience with this changer? I would like to have someone else who has one if I need some photo or detail

Plus any expert on this table would be double plus good






Attached Images
File Type: jpg Telefunken TW-501.jpg (60.3 KB, 135 views)
File Type: jpg DSC02709.jpg (76.4 KB, 130 views)
File Type: jpg DSC02707.jpg (69.7 KB, 131 views)
File Type: jpg DSC02712.jpg (41.4 KB, 127 views)

Last edited by omegaman; 05-24-2014 at 01:11 PM.
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  #2  
Old 05-04-2014, 09:48 PM
omegaman omegaman is offline
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Heres a question.
There are three positions of the lever
1. Off
2. Manual
3. Auto
When the control lever is switched all the way left to the auto position it stays there. Is it supposed to move back to the on or manual position?

I have the manual ..in German
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Old 05-04-2014, 10:45 PM
orthophonic orthophonic is offline
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I recall it is supposed to stay there.

Those were made by Telefunken under license from VM.
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Old 05-05-2014, 09:09 AM
omegaman omegaman is offline
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When the lever is left in the auto position the changer cycles constantly

When a LP is on the spindle and auto is selected the record drops but the tonearm returns to the post rest and then recycles

end of record cycles correct

With no LP and the arm down it cycles back to off correctly except in auto position

With the arm up and back and a LP on the platter, selecting auto, cycles the tone arm to the 78 position

I hope someone can explain that part of the mechanism to me

I was wondering if someone else has one available in case my pictures miss something and I need visual confirmation

Last edited by omegaman; 05-05-2014 at 09:13 AM.
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  #5  
Old 05-13-2014, 11:54 PM
Olorin67 Olorin67 is offline
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Its normal for the changer to index to the 10" position unless a record dropping down the spindle hits the 12" sensor. The other issues sound like old gummy lube, or a bent trip slide
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Old 05-13-2014, 11:59 PM
Olorin67 Olorin67 is offline
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The sonotone 8 series, really need a filter network for best sound, they used to supply a circuit diagram in the box. Like most older ceramic cartridges, they are designed to feed into a high impedance input, like several meg ohms. A modern solid state amp has much lower impedance, like 10k-50k and will load the cartridge way too much, and cut off a lot of the bass.
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Old 05-14-2014, 12:00 AM
Olorin67 Olorin67 is offline
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The later sonotone 9 series was available with a network to work into a magnetic phono input, you could probably copy that circuit.
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Old 05-16-2014, 01:29 PM
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DavGoodlin DavGoodlin is offline
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The way I understand cartridges, there are three major types;

1-crystal cartridge has the highest output, about 3 volts, rated at 80 Kilohms (1kHz) and was often used with only a pentode output tube and no pre-amp stage. 10g of tracking is needed to get that kind of output and they were physically unstable, usually needing rebuilding or crafting a replacement with a ceramic cartridge.

2-ceramic cartridge has a lower output, 0.5-1 volt and lower impedance, 47K and feeds into a triode pre-amp before the beam power pentode amp. Tracking force is still up there at 4-8g, with more expensive 2g tracking versions like the Sonotone 8T, with a lower .3 volt output, requiring a matching network as Olorin67 notes. sometimes, adding a 10K resistor across the output to match a mag phono input's impedance will improve fidelity at higher frequencies.

3-magnetic cartridge has a very low output, about .006 volts, lowest impedance at 10K and requires an additional, very low-noise stage of amplification. These are rarely found on old record players, but are common on turntables of the 70s and later.

References: RCA 1938-42 Phonograph service book, Wiki under 'Phonographs' and "Voice of Music Enthusiasts" cartridge data
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Last edited by DavGoodlin; 05-16-2014 at 01:58 PM.
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Old 05-16-2014, 03:53 PM
omegaman omegaman is offline
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Thank you very much for this information. I watched a video and the switch toggled from reject to manual. Mine does not return to manual.

I have cleaned this mechanism very well, disassembling it and lubing it

This changer was dropped on its head when in the original console so a bent something is suspect

I already had to straighten out the spindle and the record arm as they were both slightly askew and caused the drop to fail because the arm was pressing unevenly

The changer came with the Sonotone. I'll check for a circuit mod

I would love to get it working completely but its just a rainy day project

I got the new idler wheel and it is much quieter
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  #10  
Old 05-16-2014, 04:19 PM
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VintagePC VintagePC is offline
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Quote:
Originally Posted by omegaman View Post

I have cleaned this mechanism very well, disassembling it and lubing it
Is it possible you lubed something you shouldn't have? IIRC some parts in these changers rely on metal to metal friction, and lubing them means it won't work as designed.
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Old 05-16-2014, 09:31 PM
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ISawItOnTV ISawItOnTV is offline
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I have a '63 Tele Sonata with a similar table (it's mostly beige colored). Nearly drove me bonkers last year when I partially dismantled it for some resto work. I got it all back together, and it works great. Only problem I still have is it will not shut-off automatically after last record has played.
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Old 05-17-2014, 08:36 AM
omegaman omegaman is offline
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It does not help that the service manual is in German. I will have to review drawings and maybe interpret parts of the manual into English

I have been playing with it and have some more observations

As I reported above, on auto, a single record drops fine but the arm returns to the off rest.

but, If there are two records stacked on the spindle the auto mechanism plays the first record fine, setting down on the 33 position correctly. The last record drops fine but the arm returns to the off position

I did not dismantle and lube the mechanical switch so maybe it still needs to be freed up

It works great in semi-auto mode and with the new idler wheel, it plays at speed and is very (well pretty) quiet.

At higher volumes the Sonotone 8T sounds fine in the line input and too sensitive in the phono input, so this changer gets plugged into a line input
I have a new stylus for it but I'll wait for repairs to be completed before switching to the new one

Last edited by omegaman; 05-17-2014 at 02:27 PM.
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  #13  
Old 05-24-2014, 10:31 AM
omegaman omegaman is offline
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Progress

Disassembling and lubing the mechanical switch itself restored the true function of the reject/run/off switch. I just gently, gently, gently pulled up and rocked the top part of the switch until it came off, the the same with the lower part.

A few drips of light machine oil into the shaft and by the next day it was completely free

Now toggling reject returns the switch to run and the whole switch mechanism is very smooth with feather touch control

Only a few more issues left:

Stacking an LP and toggling reject, drops the record fine, but the arm returns to rest and shuts off instead of placing the tone arm on the record.
but
If I stop the hold down arm from dropping (like there's another record stacked) after the record drops, it all works great and places the tone arm on the record to play

So obviously something else needs lube/adjustment

RE the cartridge:
I am going to add the 10k resistors and see if it improves the hi freqs else a new cartridge is in order

Last edited by omegaman; 05-24-2014 at 01:34 PM.
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  #14  
Old 05-24-2014, 12:21 PM
omegaman omegaman is offline
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Well it is just an old changer

I added the 10k resistors and playing it through the pre-amp, it improved the sound considerably. Everything holds together pretty good up into "normal listening levels"

I still think the Sonotone 8T output is too low for LINE IN and still a little high for PHONO IN





And if the music is square, its because I like it square - RMN
Attached Images
File Type: jpg DSC02802.jpg (82.2 KB, 77 views)
File Type: jpg DSC02803.jpg (73.4 KB, 76 views)

Last edited by omegaman; 05-24-2014 at 12:37 PM.
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  #15  
Old 05-24-2014, 12:41 PM
omegaman omegaman is offline
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Further testing

Without the phono pre-amp it takes 3/4 volume of my 4 watts to push music out

With the pre-amp it takes barely 1/4 volume

both sound about the same really..It sounds pretty good, about as good as it is going to get with this cartridge

It's fun playing around with it

more critical listening:
Really, it sounds better without the pre-amp and with the volume higher than with the pre-amp and volume lower
with the pre-amp the sound gets brittle with higher levels

I think Deoxiting the cart pins (agonizingly brittle) made a big difference

either way, its all good

moon base alpha x-ray delta one out

Last edited by omegaman; 05-24-2014 at 01:18 PM.
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