Another Turntable Hum question

d-ray657

Ain't this boogie a mess
I just bought a CR-1020. I have cleaned it and applied Deoxit. Tested it downstairs with several different speakers and a few different CD players and Cassette players. Nice quiet and clean sound. I installed it in my main system, and got a low hum from the TT. It is a Sony PS 5 direct drive. It was running fine on a Sansui, I had it grounded, but the issue appears on both the TT1 and TT2. The hum appears whether the TT is on or off, but not if the RCAs are not plugged in. I tried plugging the TT into another outlet, with no luck. All of the other functions are clean - even the Bluetooth adapter (Plugged into the Aux RCA).

Suggestions? Thanks.
 
Frustating ground loop issue.

Unhook all other rca connections and trial and error.

Try every ground surface you can think of.
 
Disconnect the turntable ground wire and move it away from anything else.

Make sure the tone arm IC are not crossing over other cables touching them

If you have a sand alone external phono stage do not cross the input outputs IC

All of the other functions are clean - even the Bluetooth adapter (Plugged into the Aux RCA).

What is this Bluetooth adapter?

A phono stage and cartridges can be sensitive to RFI from WiFi and BT.
 
you can buy shorting plugs to put into any unused input; I do not have a hum issue, So I do not need them
 
I had phono section hum from a Bluetooth adapter too close to my Sony TA4650. Had to move it about 3 feet away. Try unplugging the Bluetooth adapter and see if hum disappears.
 
Removed the BT fob, and made sure that none of the TT wires crossed another. Hum still at full strength. Tomorrow, try another TT.
 
Removed the PS-5 and replaced it with a cheapo Technics BD-20, and the hum is gone. I wish I had thought to switch out the Grado cartridge before the switch, since Grados have given me hum issues before. Maybe this weekend I'll try out the AR XB. Long term solution is to get the Sansui 5000X cleaned and the lights replaced to I can get it back in the system. The Yamaha will serve the downstairs after that, now that I know that other turntables will work with it.
 
One more update - I now have some confidence that there is nothing wrong with the phono section. I hooked up a slightly better TT - Technics SR-DD22. No noise at all. So it will work with a direct drive and a belt drive - just not the Sony. Now playing a 180G version of Magical Mystery Tour and enjoying it.

Thanks for all of the suggestions.
 
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