2. analog
  3. 119418-1616

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
14 responses Add your response
brf
1,715 posts
 
Where is the hum coming from?  The table itself or through the speakers?  Your post suggests the table.  Try moving the Phoenix products away from the table.  Also, try plugging the Phoenix into another power outlet.
almandog OP
141 posts
 
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.
melm
1,082 posts
 
Call Phoenix.
almandog OP
141 posts
 
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. 
sbank's avatar
sbank
3,379 posts
 
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
buffyjames
38 posts
 
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.
sbank's avatar
sbank
3,379 posts
 
Harry usually does! 
almandog OP
141 posts
 
Yesterday i tried the Cheater plug and it worked. It was definitely the Phoenix Engineering power supply causing the hum.  I don't want to use a cheater plug in my system so I will move things around this weekend to see if I can get rid of that ground loop.
phoenixengr's avatar
phoenixengr
92 posts
 
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.


almandog OP
141 posts
 
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?
phoenixengr's avatar
phoenixengr
92 posts
 
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.
almandog OP
141 posts
 
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?

phoenixengr's avatar
phoenixengr
92 posts
 
Contact me directly at: info@phoenix-engr.com
almandog OP
141 posts
 

UPDATE:

I am please to announce that the issue with the Roadrunner has been resolved.

After talking to Bill at Phoenix Engineering we realized that the Roadrunner was getting power even after the system was turned off.

He recommend that I plug the Roadrunner into the wall socket to see if the LED on the Roadrunner would stop "blinking/flashing", and it did stop. It turned out that my Power Conditioner was at fault; one socket was continuously providing power when it should have been completely turned off. But no worries, I will be getting a MPC 1500.

Another thing I was doing wrong was to turn on/off the TT with the TT switch. Bill said I should use only the Phoenix power switch to turn the TT on/off, even when changing records. The power switch should be pressed until I see dashes (------) on the display, then the platter will stop. Press again and the platter start to turn. Make a lot of sense. I will revisit the manual again and drink it all in this time.

Thanks to Bill at Phoenix Engineering and to everyone for their suggestions.

Log in to respond
More to discover
80x80
TriangleART HATHOR
80x80
Lyra Etna SL
80x80
Maplenoll Ariadne and Athena with pumps