Phoenix Engineering speed control

sbank is correct, the hum is cause by a grounding issue.  The Eagle PSU uses a switch-mode power supply so the 3rd wire on the AC output is isolated from the wall socket ground.

If you are using a step up xfmr, ensure that the table's audio ground wire is connected to the phono pre-amp ground. Some SUTs can isolate this ground connection.

Try one (or both) of these:

Ground the case of the Eagle amplifier by attaching a ground wire to one of the rear panel screws;  connect the other end to a grounding point on your system.  Start at the phono pre-amp, main pre-amp, main amp or wall socket.  You may have to experiment to find the best location.

Isolate the 3rd wire ground on the table's power cord by using a 2 prong adapter; connect a ground wire to the adapter ground tab (3rd wire) and connect to your system's ground.

Phoenix engr

Thanks for the tip.
I tried your first option and it worked. The second option still cause the hum in the system. I left the unit connected with your first option. I also notice that the Roadrunner display continue to flash when I turn my system off. The Eagle display goes off fine, no issue. I have to unplug the roadrunner each time after use. Any idea what is going on?

Can you clarify: display flashes?  Does it display 5 dashes or an RPM reading?   You can put the display to "sleep" with a long press of the on/off button (back panel) or it should blank ~ 5 minutes after the platter stops rotating.  Sometimes, surges or static shocks can cause the sensor to trigger which will take it out of sleep mode, but it should blank again in 5 min.

All segment in the each digit lights up while it flashes. I held the switch down on the roadrunner as suggested. It did not stop flashing after holding it down for two minutes. The Turntable is off while this is going on. I had to unplug the roadrunner for the display to quit flashing. 
Any idea?

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