VPI Analogue Drive System

Keeping the speed at 33.3 is an important function of a speed controller, but it is not the most important thing. Maintaining that speed without micro-speed changes is even ore important and is heard in better, smoother, sound. I can vouch for the ability of the SDS and the Eagle to achieve these goals--and the Eagle (or Falcon)/RR combo is a particularly elegant and simple way to do both.

The VPI ADS can do it, but it is a machine that has been plagued by problems traceable IMO to a less than the best design and the use of very cheap parts. Do you watch "Shark Tank?" Do you know what margins are? I, personally, would not buy one of these things.

At the same time Bill Carlin (Phoenix) has published DIY material for people to make their own speed controllers and it looks like some people may be getting together to turn these out--either as kits or built. If I had to decide now, I would get something I could sell easily (like an old SDS or VPI PLC) and wait to see what happens.

For a tech view of all this have a look at http://turntablepsu.com/vpi.html Though unsigned, it’s probably written by Bill Carlin; nobody knows as much as he does about this stuff.

The Southerland device referred to above, by the way, is NOT a speed controller. It’s just a very expensive strobe.

Running your TT at the right speed (or nearly so) is not a tweak.  It's just a very basic thing everyone should do, like leveling the platter.

I used an SDS for many years.  A bullet-proof device.  As for noise from it; there wasn't any at all.  I replaced it with an Eagle/Roadrunner,  Performance, as far as I can tell, is identical--but for issues that RR addresses.  Odd to hear about any noise issue with the SDS.