SME 20/2 Finger Lift Hum

Dear Rsnoceanview: IMHO is a problem with an ungrounded tonearm or/and TT. Even that you already try every ground combination could be that the ground wire in the tonearm is ( for whatever reason ) not soldered.

I think you have to check for continuity with a multimeter as other ground connections.

Regards and enjoy the music,
R.

IMO, if there were an overall issue with grounding the tonearm (i.e., if there were a potential difference between his tonearm and his phono stage, for example), the hum would be audible at all times, whether or not the OP touched the finger-lift.

Unless the person touching the arm was also simultaneously touching another another component which has a different potential, I don't see how this is a ground loop. It seems like the person's body is acting like an antenna.

The easiest solution would be to cover the armlift if this really is a problem (perhaps shrink wrap with heat applied directly to the wrap and not to the cartridge itself).

Hi Larry, That's what I originally suggested - insulate the arm lift OR don't touch it. If the system is elevated from true ground for some reason, for example due to a faulty wall socket, it is conceivable to me that one's body could be at a lower potential. When you contact the arm, only then is there a loop. There are several variations on this theme, but I hope you get my idea. The body as antenna usually results in a higher pitched noise, not true hum.

Also, if the tonearm is grounded to the phono stage, as someone else suggested, it might be of interest to un-ground it. If we then don't have hum, my hypothesis is supported. Anyway, changing the current grounding scheme, whatever it is, might reduce or enhance the problem, and that information would be valuable.

All grounding effects have been tried (on the SME there are three into two grounding cables from the arm). None, either one, both. No change. Checking additional items, there is no hum (and it is a hum, not a high pitched sound) at the arm tube, headshell or cartridge body. But there is at the finger lift, tops of the headshell bolts and the front bolt on the Lyra. For now, have insulated the finger arm with plastic, but would like a permanent solution. That could be a new cartridge or replacement of the stainless steel bolts/screws with non-conductive bolts/screws (nylon or carbon fiber?). Has anyone tried that and if so where to procure? Thank you.