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Grounding a turntable with no ground connection

Yes, I have tried several interconnects. I'm running with some double shielded ones. It has been busy over the weekends so the turntable has had a reprieve from disassembly. Perhaps in 2 weeks I'll dig into it.
 
Have you checked out the cartridge coils to verify the cart is still good. I had bad hum in 2 cases now. One was a technics u-25 destined for the bin....humm city. The other was an ortofon on a dual 604. I had to transplant the cart body of a 505 into the 604 headshell because of the proprietary sleds.

I was searching for the source of humm in both instances for quite a bit before I checked the carts. Problem solved by installing new carts in both instances. As an aside...I ultrsonically cleaned the u-25 cart in alcohol as it was fubar, but the cleaning made it sound lime new again. LoL
 
Turned out that the negative wires off the stylus were shorted in the tone arm. No easy way to take it apart. In the end I picked up a Audio Technica AT-LP120XUSB. No hum! Same wires, same everything else.
 
Indeed I removed the Teac preamp from the circuit. The last state of the Teac was the tone arm wires going directly to gold plated RCA jacks. Still had a solid hum. The new TT with the same stylus resulted in dead silence!

Bottom line is if the negative stylus wires are shorted some amps will experience a 60Hz hum.
 
Mark Casazza said:
Turned out that the negative wires off the stylus were shorted in the tone arm. No easy way to take it apart. In the end I picked up a Audio Technica AT-LP120XUSB. No hum! Same wires, same everything else.
Click to expand...
Well it's too bad you had to resort to using a different table.
 
That was my thought as I started this venture, but in the end I redid all the wiring that was not in the tone arm. There could be a bad connection inside the tonearm where the head shell connector attaches to the wires. They built it so it is not coming apart and going back together again so I could not inspect and fix it.
 
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