Replace VPI TNT rubber belt with nylon thread

If you're even considering this then you need to have a speed controller as well. The different diameter of the thread vs the rubber belt will result in a speed difference on the platter.

Basically you need a non-stretch string, nylon or silk seem to work best. You will probably need to give the platter a starting push with the string. The sound difference / improvement is very noticeable. Better PRAT and detail retrieval with the string. Notes seem clearer and unsmeared.

If you don't have a speed controller you could try putting something heavy and smooth up against the rubber belt where it comes off the motor spindle before it gets to the platter. You just need to touch it enough to damp those nasty vibrations travelling along it.

I agree with Ptmconsulting completely. I am using 0.004" nylon string with SDS controller.

It sounds more detailed and clearler. Bass seems better defined. Sounds like high frequencies are better defined. It seems to have less bass, but bass is better defined. If your system is bright in the beginning, you may not like it.

I am going back and forth with this and still trying to find which way is better in my system.

Thanks to both. Advice is very helpful.

I use non-flexible nylon string with speed contoller. I find the speed is 6% faster with the nylon string. For the sound, I find it cleaner with less coloration (or less rubber belt sound), tone is more natural, image is 3-dimensional, bass is better defined and improve tonal balance a lot. Exactly what Sojs commented. The background sounds quieter and darker, probably due to more stable speed and no motor vibration is being transferred through the belt to the platter.

But I get small motor noise comes out from the motor spindle. I don't know why. Is the tension too tight? Can this be resolved? Really apprieciate is Ptmconsulting or Sojs can give advise.

San

The string shouldn't be overly tight. Just enough to keep the slack off and make the platter spin. too tight and it seems to constrict and over-control the platter. Let the mass of the platter do its thing.