High quality AC turntable motor

Just a thought, but have you tried a new belt and a good cleaning of the motor pulley and subplatter belt contact area? The stylus drag you are hearing sounds like compliance being introduced through belt slip or stretch.

If you can find one, I've found the Berger-Lahr motors to be considerably better than the Crouzet, Hurst or Saia, at least in terms of cogging. Unfortunately, the Airpax/Premotec motors are rather difficult to source however they offer the smoothest cogging characteristics out of any of them. Then again, I use a Mark Kelly Synchrotron controller, so I can null out most motors so that cogging vibration isn't too much of an issue.

Good luck and keep us posted.

I had a problem a while back with my Nott. seeming to drag some. I lifted off the motor pulley and discovered some hair wrapped around the motor shaft and wedged into the bushing. Removed it and everything was hunky-dory.

Lohanimal, a mains sign wave regenerator is what you need in the context of a controller for an AC synchronous motor. "Angling the power.." Sounds to me like another way of saying the same thing, hopefully. Perhaps the K K will be cheaper, but it ought to be much like the Merlin.

Hi Lewm - sorry for my lousy phrasse 'angling the power' I understand that with a 24 pole synchronous motor they can be made with 4 coils. If 2 opposing coils are driven, and then the other ones which sit at 90degrees to the driven ones are also driven then this ought to significantly reduce the ripple. PErhaps a fair analogy would be a two stroke to a four stroke engine. If it is the case that we have a higher torque motor, it's the magnets that help increase the torque, along with the commutator windings and thickness. As this increases, so does the clunking/cogging. That is why I want something that helps reduce this. A pure sine wave regenerator simply re-creates the 50 hz - it does not provide me with those 90 degree opposed waves to drive the other 2 coils. I hope that I make sense andd am barking up the right tree.

It seems to me that some of the posters here have forgotten some of their Trig. A complete sine wave cycle is 360 degrees. As the previous poster stated one set of field coils is driven by the primary AC current and the other with a AC current 90 degrees out of phase. This phase shift is usually accomplished with a capacitor (the current though a capacitor is 90 degrees out of phase with the voltage across it). Now, a sine wave generator with TWO amplifiers (thus two outputs), one 90 degrees out of phase, with the ability to "trim" the phase angle between the two has the ability to null out almost all motor vibrations. This is a distinct advantage over those sine wave generators with just one output. I own a Nottingham Wave Mechanic. I recently had it open to replace an output transistor that failed (it doesn't do too well with a single ended output stage). There is NOTHING special here. If the parts cost more than $125 I'd be surprised. Yet it retails for something north of $1200. They don't call us Audiofools for nothing. That's one reason I'm committed to DIY. Kevin's kit should provide a lot more "bang for the buck". The OEM power supplies are usually nothing more than an oscillator, a cheap amplifier and a transformer to boost the voltage output of the amp to 120V.