Thorens TD160 hum

[Jeffhill]

Hi all. Looking for some guidance and experience here. I have a Thorens TD160 and was getting significant RF Ingres, a local AM radio station, coming through loud and clear on my phono channel.
I just replaced the original interconnectors with Synapse High Performance Multi Media interconnectors by Belkin with a ground line.
I was pleased that when I started up my turntable the radio station ingres had disappeared but I now have a hum on the left channel.
When I disconnect the ground on the receiver the hum goes away but the AM radio station returns, although not as loud as prior to replacing the interconnectors.
Any ideas, thoughts on what the issue may be?

 

[Jeffhill]

The Thorens TD-160 default ground scheme is to ground the shield of the right channel (green). WHen you connect standard RCA phono cable without an external ground lead, you are already grounded by default. Then, when using an external ground wire (in addition) it creates a ground loop which manifests in humming. So the default grounding scheme must be altered before one can use an external ground wire. The radio broadcast through the phono stage is obviously an amp / preamp issue which you accidentally mitigate with the extra ground wire that serves as a grounded antenna. The am station audability is not a fault of the turntable.

Thank you for the feedback.
Could I ask how do you resolve the ground loop?

 

[bberkom]

Either disconnect the internal ground for the cable shield or don't use the extra ground wire.

 

[noisefreq]

After you get the grounding sorted out (I kept mine stock), you could try Ferrite Beads on all the AC cords of your turntable's signal path.

 

[Jeffhill]

After you get the grounding sorted out (I kept mine stock), you could try Ferrite Beads on all the AC cords of your turntable's signal path.

 

[Jeffhill]

[/QUOTE
Thanks all. I disconnected the metal tab from the ground and the hum is gone. I still have a bit of Ingres from the local AM radio station.
Any idea where I could find the ferrite beads?

 

[noisefreq]

Mouser, Amazon...just goggle it, they're cheap.

 

[Jeffhill]

Thanks!