Nottingham motor controler

Inna, don't let the comparatively low price of the Falcon PSU deter you. It's got a lot of functionality built into that small case. You can do speed and voltage calibration. I'd at least investigate a bit. No affiliation to the manufacturer, just a happy customer.

There is another PSU from the same company, a little more expensive.
I would still prefer, I guess, what is recommended by Nottingham, but I'll have to think further. No rush.

Inna, the most important mod was to the plinth. I used an aluminum / Baltic Birch plywood / aluminum sandwich, and further isolated the motor. Also went to an air bearing tonearm (big difference).

If I remember correctly, NA will match the WM to your motor. Of course, that means sending it to them and being without for a few weeks. But new motors are not expensive from NA - and with the cost of courier ... and then you don't have a new motor with new bearings ... and you don't have a spare motor ...

I have experienced no blown transistors or other problems. I also protect the WM with an isolation transformer.

I see.
I took a look at the Walker motor controller and read some reviews. I think, it could be significantly better. Some Nottingham owners use and really like it. Damn expensive, though not so for a Walker - look at his turntables.
I should't have looked, anyway.

If I remember correctly, NA will match the WM to your motor.

Unless Nott. has radically changed the Wave Mechanic in recent years I don't see how this would be possible. The unit that I owned had only one adjustment, frequency, to adjust the speed. It had one output and relied on the capacitor in the motor pod to define the phase difference in the AC current to the two field coils of the motor. It is my understanding that Rega in some of it's pricier TTs had a two phase controller that allowed them to trim the phase angle of the AC current at the factory to the individual motor. This is precisely what one can do with the K&K unit. IME with the K&K controller having the ability to adjust the voltage of the output is as, or maybe more, useful for improving SQ.