Phoenix Engineering speed control


I purchased the Phoenix Engineering speed control for my VPI Classic 3. I purchased  the bigger power supply and the tachometer combination of the speed control.  I notice that I can hear a steady hum coming from the speakers when the speed control us turned. The hum is constant and will not vary if I turn up the volume on the Preamp.  But the hum goes away when I turn the turntable off. The hum return when I turn on the turntable again. I even in unplugged the interconnect from the turntable, but it make no difference.  Does anyone with the Phoenix Engineering speed control experiencing the same issue?
almandog
The hum is clearly coming from the speakers when I turn on the tuentable without any record playing. I plugged out the RCA interconnect from the turntable and turn on the turntable again and the hum is still coming from the speakers. I even move the Phoenix Engineering speed controller around under the VPI Classic 3 turntable, but I could still hear the hum. It is not coming from the turntable because I removed the RCA interconnect.
I will call them tomorrow. 
I am listening to some records now and I can still hear the hum before I start the record.  I disconnected the Turntable from the Phoenix Engineering power supply and the hum disappear. So the Phoenix is definitely is causing the hum. I even put the Phoenix power supply on the floor away from other power cords, but it made no difference. The display on the Phoenix is working fine: 33.3 RPM on the main display and 33.334 on the racometer. So it's seems to be doing the job. But the hum from the speakers is a mystery. 
It's probably a ground loop. Do the table and/or the Phoenix have a ground wire? Try a cheater plug. Experiment with whatever ground wires there are between them and share the results with Phoenix when you call them. Cheers,
Spencer
I agree with sbank....its a ground problem. If you use a cheater, only use it to confirm a ground issue...don’t keep it in the system....they ruin the sound. Use a voltmeter to see that all wall plugs are wired correctly. This can be very tricky to find.  I would get in touch with both Phoenix, and VPI and see if they have suggestions.  If I were in a betting mood, I would say that Harry has the answer.