Direct drive vs belt vs rim vs idler arm

Dover... great writing and I can agree with most of what you wrote...

Robert fulton did do testing and experiments and of course most important listening ...his conclusions where that hi profile line contact elliptical ect etc... in a pivoted arm causes "lots" of distortion (audible)due to the fact of cantilever twisting...and in fact maybe do to hi freq phase anomalies because of the twisting

moreover you maybe right on why we hear differences in everything because of the servo/drive/electronics etc..

please carry on

Lawrence

Fidelity Forward

Peterayer...Yes i totally agree if it was not for a lot of people on these forums starting to demand better performance then no company would be willing to invest in our little hobbies!

Manufactures do read the forums!

Lawrence
Fidelity Forward

Dear Dover, That was a nice post. But as regards your "old" Sota Star, I had a different experience with my old SOTA Star Sapphire Series III. I owned it from about 1990 to the late 1990s. This was the turntable that made me a believer in the potential deficiencies of belt drive. I could easily hear the pitch instability, particularly on jazz and classical piano LPs. For all that time, I put up with it, because I thought that the distortion I was hearing was on the master tape from which the LPs were made. (There was no internet in those years to tell me I was wrong.) Then I bought a Nottingham Hyperspace, which is not too different from the SS in design philosophy but is worlds better in its accuracy of reproduction of piano music, i.e., pitch stable, elastic belt drive notwithstanding. When I added a Walker Precision Motor Controller to the Hyperspace rig, everything went up a notch further; the Walker made a huge improvement in what I already liked quite a bit. These experiences led me to begin to appreciate the importance of drive mechanisms and the proper job of a turntable. I hasten to add that, from what I have gleaned second hand, the modern SOTA turntables are also much improved over my old Star Sapphire. I mean no slur on their current products.

Yes, the modern Sota uses an AC motor and electronic power supply in lieu of the previous DC motor. My Cosmos IV seems dead on, and since the motor is mounted to the same suspended sub assembly as the platter and arm, there is no movement between them, unlike most suspended tables where the motor is fixed and the platter/arm is suspended.

Still no comment on my interpretation of the Fat Bob's video after dropping the cartridge?

Lewm - same experience, but from the motor & power supply mods we did, the cogging in the early motors on the SOTA was significant. According to our tech the "cogging" was induced by shortcomings with the power supply regulation on the papst motor board, not the traditional cogging as in poles/slot rotation of the motor itself. That being said, the motor/platter should be rigidly coupled for stability, and obviously SOTA addressed this issue later by mounting the motor on the same chassis as the platter & arm.
After the SOTA I temporarily used a Townsend Rock with the ET2 and the stability of the fixed plinth design was apparent, despite the sloppy build quality of the early Townsend.