Thorens TD125MkII upgrades

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I have a thorens TD125MkII with ADC Carbon Fiber low mass tone arm and Grado Refrence Platinum cartridge. I refurbed the table by cleaning all of it, replacing the belt, replacing the bearing oil, and polishing the bearing and shaft as much as I could.

I have also thought about upgrading or improving the power supply. I figure it could make a large difference in much the same way as the Linn does, but wasn't sure how to go about it. I had heard that the Linn power supplies, so maybe the ebay available Hercules, could be fitted, but I wasn't sure how. I also don't know how the voltages of the two motors compare, along with the speeds they run at. Can a Linn LP12 motor and controler be exchanged for a thorens motor, or do they run at different speeds?

Ok second Idea I had was to replace my arm. I had thought about putting the SME arm on it, as that is the most commonly seen arm on this table, and I know some compare it with some of the best when upgraded, but they get a lot for a pretty old arm.

That brought me to the cheaper and maybe better option, a Rega arm. I can get a Moth version for 200-300 dollars, and in the 400 range with incognito wire. So, is the RB250 arm a clear step down from the RB300, and if so, is it worth the extra money for the 300. I have heard some prefer the RB250 to the 300 because of the antiskating. Is the incognito worthwhile over trying to do the same myself with say raw cardas wire?

Will the Rega arm match with my table ok? I hear some people talk about the rega being a bad match for suspended tables, but I'm not really sure why.

Last idea I had was for the main bearing. I hear people commonly talk about upgrades to the main bearing, and was wondering what I could do to mine. One Idea I had was to fashion, somehow, a teflon thrust plate for it, but wasn't sure if that was a bad idea. I think it has a polished steal thrust plate now, but I'm not sure of that?

Also, has anyone seen the platter upgrades from www.designbuildlisten.com, they offer a platter that slips over any turntables spindle, offering a better platter. I see problems in that you know have, I would think, a very tall platter, and it could potentially increase wear on the bearing, while reducing stability. Would the upgrade to the platter be worth it?

Thanks for any help you can offer in my quest for better sound.
 
I figure it could make a large difference in much the same way as the Linn does, but wasn't sure how to go about it.

why do people think that upgrading a power supply that works fine does anything to the sound?
The darn thing has to do one thing only - to keep the speed dead on, without deviation. As long as the thorens does that - why worry?
Claims that different motor controllers do wonders - I have to wonder as to the sanity of the claimant.

I had rega B300, fully modified. Now I have the sme 3009/ 2, for about the same price - but a lot better (on my transcriptor). The rega arm seemed to have extracted the last bit of surface noise from the record.
I think the rega arm works with neither - mine was on a non suspended TT.
I run an MG 1 airbearing arm on the thorens, and both this one and the sme are much better behaved than the rega.

As to the platter - it can ring quite a bit - if it influences sound with a mat on top??? Anyway, I applied some damping material to the platter.


As to quest for better sound -

1. make sure the least amount of noise gets tranferred through the platter to the pickup system
this includes ambient sound from the speaker/foot fall and TT generated sound - bearing and motor.
2. Make sure it runs on speed and stable
3. make sure the bearing is clean and noiseless
4. Make sure the arm/cartridge combination works ( resonance frequency)
 
Well as for speed, I hooked my multimeter up to the frequency counter mode with a record and a 1000hz test tone. What I found was that the frequency changed between around 996hzish and 1005hz, and the biggest issue actually came with a sweep tone that would move in steps. Moving from low to high didn't show any issues, but moving from the high to low showed the tone change frequency, running a bit low at first and then correcting. This makes me think the power supply is not doing a good job controlling the speed, but its parts are quite old as well, and could just need replacing. This is what prompted me to consider the upgrade.

I will say, I have heard a Linn with a Lingo power supply and a Valhalla power supply, side by side, for extended periods, and was quite sure I could hear differences between the two. I wouldn't wager money on it though, which also implies the differences were small at best, and possibly not worth my effort.

Like I said, I already did what I could to make sure the bearing was not making noise, and best as I could tell, its not. Like I mentioned, I polished it using a kit I bought that had a special tool for getting into the bearing itself, and I simply hand polished the platter shaft until it was very shiny.

As for the tonearm. If the two were the same money, I would conser the SME, probably even go for it. However, like I said, SME's are going for 400-800 dollars in stock form. I would then want to rewire it, figure another 100-150 dollars, and probably want the knife edge bearings for another 200 dollars or so. That probably turns it into a truely wonderful tonearm, but even at the minimum cost, its more than a rega. As I mentioned, the Rega in OEM form, i.e. the Moth Audio Mk1 and Mk2 tonearms, are in the 2-300 range. That is quite a bit less than an SME. When I then include the rewire and various other mods, the price then at best matches the SME's starting price. Thats why I was leaning in that direction.

I'm inclined not to believe it, and I have no refrence to be sure of, however, My grandfather is the one who gave me this Turntable. He bought it with an SME arm and durring the whole 80's Low mass craze, he purchased the arm I have now from ADC. I wish he had kept the SME so I could have compared, but he always insisted that the ADC arm was better. I never asked this specificly, but I will bet he purchased a new cartridge at the same time, and maybe the improvement he associated with the arm was actually more to do with the cartridge, which was a Shure V15MkIII I believe. Prior to that I think he had either a stanton or empire cartridge, which I know he didn't like much. Anyway, I mention this becuase I have always been afraid to upgrade arms only to find my grandfather was right and the ADC arm really was better. I've never heard of anyone who loved this arm, but I don't know many who have direct experience with it either. I wish it matched MC low comliance cartridges better, thats my main reason for wanting to change arms, I want to try a Denon RL-103R or whatever the model number is.
 
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Hi pjpoes,
A 2.5 Kg platter does not change speed that quickly. It can't. That and the motor pulley is clutched. Your album may be slipping, or the test record may be cut that way. The better test may be to use a frequency to voltage converter and record the results on a DSO or chart recorder. I don't know how much jitter may exist in the counter reading or it's update rate.

Another thing to consider is that the power supply hasn't got much to do with the wein oscillator that runs the motor. As long as the supply doesn't collapse (it's not), your table will run fine.

I still suspect you should have more concerns with your record and counter method than the table.

-Chris
 
Yeah I will give you that I have no idea if the method I used was sound. I don't generally found that or SPL meters very effective ways of measuring how well something is reproducing tones in a stable fashion. I do still question this conclusion that power supplies don't affect turntable performance though. I have not yet heard in my own system, under conditions I fully trust, an upgraded power supply compared with the original. However, I have heard upgraded power supplies on turntables, even right next to the regular one, and felt that I could hear a difference.

I had another idea for measuring the performance, I was thinking I could record various tones from a test record, and then looking at those on my computer. I have various test records, some are old and worn, but I have 3 that are almost brand new. Oddly enough, people seem to buy these and then sell them at rumage sales and record shops quite cheaply.

All of this really is besides the point though, I am more concerned with the idea of changing the tonearm. If anyone has feedback on that, it would be appreciated.
 
995 -105 HZ is a 1 cent total pitch change. This will be very noticable as a strong wow. If you can't hear this, there is either something wrong with your sense of tone pitch, - or- more likely something seriously wrong with your measurement. I don't have the service manual at hand, but IIRC the strobe light is crystal based, so the change should show up really well in the strobe pattern.

You may have noticed that I started a similar thread just a few days ago.. I recently got hold of a 125 in good condition, but without arm. I do have an SME II-i , but I was looking for possible improvements in the area of plinth, mounting etc. I really don't think I will bother making a new PSU...
 
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Hi AuroraB,
995 -105 HZ is a 1 cent total pitch change. This will be very noticable as a strong wow.
Yes! I've never heard a TD-125 do this. Belt slippage could cause this but it would be a slow change due to the inerta of the platter. A quick change must be slippage on the mat.

Power supply mods will not affect the motor drive circuit in this table. The strobe is run off the AC mains.

-Chris
 
anatech said:
Power supply mods will not affect the motor drive circuit in this table. The strobe is run off the AC mains.

-Chris [/B]

If you say so -I believe you!! ( I have several TTs, so I prb'ly mix up some schematics )

OTOH even if the strobe is mains driven, an abrupt 1 cent change in the mains frequency, and back - and forth, is almost impossible, - so the change should still be visisble in the strobe pattern.
 
Guys,
a bad motor controller of a TD125 can do those nasty things pjpoes reports. I've gone through this. In my case I could look at a back-and-forth wandering sine-wave on my scope using a test record.
I do think good on the 125, but I don't on the controller. I couldn't fix the issue even in the long run and I ended up using a outboard motor from transrotor. Much better now!
Rüdiger
 
Hi Chris,
this peticular one couldn't, the board just had seen to many repairs and the copper traces fell off while soldering new parts! The speed change however isn't rapid, but consistently 'dancing' between too slow and too fast, and it's quite possible that a digital freq. counter then oscillates between say 998 and 1003 Hz!
Rüdiger
 
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