TT-101 turntables…or any DD decks


It’s funny how in audio…..I’ve had many mishaps over the years which have led to ‘forced’ improvements in my system…..

The latest happened just 3 days ago when the ‘Power’ switch on my 35 year old JVC/Victor TT-101 turntable failed to ‘turn-off’ when pressed……leaving the unit ‘powered up’ with three diodes continuously on……
I thought to myself……time to have the unit serviced and all the capacitors replaced (at least)…..

I have thus been listening over the last three days and nights and have been struck by the perceived improvement in ‘sound’?
Everything seemed better….the timing….the solidity…the noise-floor….the subtlety…..the transparency…..
And then it hit me……
With solid state gear…..I have always kept them ‘powered on’.
My Halcro DM-10 Preamp is always on ‘Mute’ (as was the valve Kebschull before it and the SS Electrocompaniet before then).
My Halcro DM-58 Monoblocks are always ‘on’ (as was the Perraux PM-1850 power amp before them).
Most DD drive turntables I know of are all solid state……
Why should they be any different?
Why would they not benefit from the capacitors being fully charged with the transformer/power supply, PCB, transistors and resistors fully ‘heated’?

This for me…has been a more significant improvement than ‘nakeding’ the ‘nude’ Victor which I recently accomplished…

It’s such an easy thing for anyone to try out….there is simply no ‘down-side’……other than the diodes burning out? :-)

Happy listening…..and Happy New Year….
128x128halcro
Lew, try to determine if the noise is coming from platter friction due to contact with the metal housing of the turntable. Any slight lowering of the bearing height will result in scraping of the platter. If the motor was removed then check that the washers to support the motor are in place.

If the noise is not coming from the platter then it must be from the motor. I have experienced a similar scraping sound at 45 rpm but not at 33 after oiling. It was due to incorrect bearing height as the bearing screw was not repositioned exactly where it was originally. I doubt if your TT needs oiling...if it did then it should produce sounds at 33 rpm.

Lew I would carefully mark the position of the bearing screw before unscrewing to oil the bearing or adjust. It is easy to do with a marker pen or simply just score the screw and the housing with a thin bladed screw driver.

The screw actually determines the height of the bearing and thus the central spindle for the motor. There is actually a round metal plate that could scrape a pc board inside the motor. Too low and the plate would scrape but too high and another part of the motor would begin to touch the housing causing friction.

What I would do in your case is to simply mark the bearing screw position and screw clockwise a tiny bit ...maybe 1mm and check the result. If it does not solve your problem then try again.

Hope this helps. I am not an expert and take no responsibility if you in any way damage your TT or bearing. I am just relating my experience.
Dear Dickson, Thanks for all the suggestions, but as I wrote earlier, the bearing was never messed with, nor was the motor per se ever removed from the main chassis (at least not by me or Bill Thalmann), and I did check to see if there was visible rubbing or any physical contact between the rotating platter and the well in which it sits, and I could detect none. Moreover, now that I think of it, the noise should be present at 33 as well as at 45, if it's simply a matter of platter height and "rubbing". Yet the unit is silent at 33, or at least silent enough that I do not hear the noise from about 2 feet away at 33. (Probably should get out my stethoscope.) We shall see.

Oh, and the last thing I would ever do is to hold you responsible for anything. I am no virgin when it comes to DIY or direct-drive.
Dear Lew, Even if the bearing or motor was not tampered with, there can be slight wear of the bearing plate resulting in the bearing sitting lower.

As mentioned I experienced the same symptoms that you have. On 33 there was no scraping sound but at 45 there was a scraping sound. I cannot explain why this would only occur at 45rpm and not at 33rpm. Adjusting the bearing screw solved the problem.

I also have a TT-101 motor that I have opened up and there are three thin washers separating the top and bottom motor cover. If I omit the washers and spin the motor manually there is a scraping sound due to the motor touching the upper motor cover.

You can experiment and raise the bearing spindle by turning the bearing screw just 1 millimetre at a time and checking the 45rpm speed after each adjustment. I remember I only had a range of adjustment of about 6-8 mm.
A couple of thoughts: I have left my TT-101 powered up continuously for months now. I start it spinning when I want to play. No apparent ill effects and no problems with power supply glitches that were starting to appear before I adopted this approach.

I concur with the suggestions to Lew that the motor height is off slightly leading to the scraping sounds. Both suggested solutions: checking the screws that hold the motor cover in place - they use two different metal washers, stacked,and adjusting the bearing cap are the right ones. I would also add that the motor itself is screwed down onto two thin washers (that I replaced with rubber/steel)

Inside the bearing cap is a white nylon or similar thrust pad that on mine has an indentation where the ball sits. I wanted to take it out and replace it with Lignum Vitae but was unable to remove it without causing damage so left it alone.

I believe that the indentation in the thrust pad is original but have no evidence for that - it could have been worn into it by the years of rotation. I tend to believe that the ball is held by the end of the spindle (it is cupped) and rotates on the thrust pad which because of the indentation has a rather large contact area with the ball. To my thinking this creates a large area that needs lubrication and it is critical that the lubricant is not squeezed out leaving a dry center - so I used a 5w-20 Mobil one that I have on hand. Next time I take it apart I will switch to an even lighter synthetic (0w-5 Redline Racing).

The ball I put in is Si3N4 (Silicon Nitride)and it is 4.06mm in diameter (even though I bought it at 4.0mm and the original steel ball is 4.01 mm it all seems fine).
Aigenga, I have some of that Redline Racing oil. It was recommended by Howard G Stern for use in the Kenwood L07D bearing. (Howard is the L07D guru and keeper of the L07D website, not the radio jerk.) Thanks to all for your suggestions. At the moment, I sent off the TT101 for repair of a persisting problem that neither I nor Bill Thalmann have been able to cure. I don't expect to have it back for a few months, but I will keep the ideas in mind. If the problem cannot be fixed, the rubbing noise is not going to concern me very much; I will have to put the TT101 on display as a museum piece or use it as a doorstop or a boat anchor.