SME 3009 feedback

[Davidjsch]

Would like to ask for some help in tracking down an irritating issue….

l’ve a 3009 imp fixed mounted on a Thorens TD 160.

there is a hum across both right and left - not much but audible.

of more concern to me is feedback when I touch the arm when the stylus is in contact with the record. Lift the arm , no feedback.

I‘m attaching a photo of the ‘workings’ in case anyone can identify any issues….

be grateful for any ideas…

 

[DasguteOhr]

I would guess internal wiring of the tonearm. When the angle of the tonearm changes, the cable touches the inner wall of the tonearm. Most of the time the cables rub through the transition from the tonearm tube into the shaft. Get a multimeter for ohm measurements and measure the wiring. Attention please do not measure that with cartridge, remove the cable there. DC voltage is not good for cartridges.
Signal wires on the left chanel (white)and right chanel(red)must not have any continuity to ground and earth wire

 

[mtemur]

Try connecting tonearm ground directly to ground connection on the back of turntable and removing turntable ground wires.