LP12- Power Supply- Need education

None of the power supplies mentioned here, including any of the Linn options or the VPI PSs, incorporate a feedback mechanism whereby instantaneous changes in platter speed can be sensed and corrected. What you do is to set the PS such that your platter is turning at 33.333 rpm using one or another technology (recommend KAB strobe device)  to monitor the speed while you set the power supply. After that, the platter is on its own; the PS cannot account for belt slip, belt creep, stylus drag, etc. Phoenix Engineering made an aftermarket power supply with a separate tachometer that connects to the PS and feeds back speed errors that could be due to any of the above, which are then corrected.  PE no longer markets these devices, but SOTA has worked out a deal with the PE engineer, Bill Carlin, and essentially PE equipment can now be purchased through SOTA. Some think this sort of mechanism introduces new problems due to the act of correcting the aberrant speed, which, such persons think, has the potential to be as audible as is any momentary degradation of speed control.  I don't agree based on my personal experiences.
The mentioned method of running the turntable motor on reduced voltage to reduce noise does not always work well with all types of motor, and carries with it the penalty of a loss of torque. In fact, I think at least one of the VPI devices works by lowering voltage and/or current. I don't know whether Linn uses an AC or DC motor, but if you can adapt an AC synchronous motor to your Linn, then in my opinion the very best option is to buy such a motor and the SOTA/Phoenix Engineering products to run your Linn.  In my experience, ANY competent motor power supply makes a huge upgrade for a belt-drive motor, but the PE stuff is the absolute best.
I am not a big fan of suspended turntables with lightweight platters, but if I had to optimize one, I'd go that route.  I do use the original PE gear to run my Lenco, and I am very happy with the results.

None of the power supplies mentioned here, including any of the Linn options or the VPI PSs, incorporate a feedback mechanism whereby instantaneous changes in platter speed can be sensed and corrected.

You’re incorrect, both the Linn Lingo 4 and Radikal use sensors in a closed loop with a speed control which monitors platter position once per revolution. The Lingo 4 accomplishes this with an AC motor and the Radikal a DC motor. I have direct experience with both and they are at the very least equal to the Phoenix Roadrunner/Eagle (I owned and used both Phoenix products on VPI and Basis turntables.).

@saburo   +1


There is, as usual, a ton of misinformation and pure 'BS' being foisted by those who really have absolutely no clue about the sound of a well set up Linn LP12. 
I love this from mijostyn...'listen to a Linn platter, you will be able to pick up radio stations'..ridiculous!

Millercarbon, the power cord made a difference only because you wanted it to. In reality it did not make any difference. Don't feel like I am picking on you. I sometimes have trouble separating psyche from reality. I have never used either turntable you have mentioned and can not speak to their performance. If you had problems with them then I would have to believe they were either not set up correctly or were not good examples of suspended turntables. Neither the SOTA or the SME are sexy turntables. The industry knows that if you make something look sexy enough many people will think they sound better. The reason most turntables are not suspended is because it is not an easy thing to do.
You either have to make it massive so that any additional mass (the tonearm) is trivial (SME) or create a system were in you can compensate for the mass of the tonearm (SOTA). Both turntables are far more accurate than the resolution of your brain to detect any speed variation flutter, wow or otherwise. All you are going to get out of a more massive platter is higher shipping cost and faster bearing wear. 
Very few upgrades result in "huge" improvements.  I think you minimize your opinion by describing variations this way. Whenever I hear "huge," "dramatic," "incredible," I automatically turn the comment off. 
I heard a demonstration comparing a Clearaudio Statement/Goldfinger combination with an SME 30/12/V12/Goldfinger combination and if there was a difference I certainly could not hear it neither could anyone else I talked to. None of us knew what was playing at any specific time until the end of the demonstration. 

Davey, I lived with LP12s for 10 years. The only thing I have nice to say about it is that it had a dust cover. The only reason I stuck with them is because until the SOTA Sapphire came along everything else was worse. You want to know how crappy the LP12 is? Get your self a SOTA Sapphire.