Unexpected Hum

[prepress]

Hello all,

For the first time since July I was going to play a record. I pulled one out at random to test the new settings on my C2300's MM input to see if I got it right (I'm attempting to increase the gain), and noted the hum coming from the right speaker. I turned everything off, went behind the system and the ground cable seemed a bit out of order. I re-seated it, turned the system back on, put the record on again, still had hum but now no music from the same right channel. I hit the Mono button and got sound from both channels, still with hum from the right channel only. The hum goes up and down with the volume.

I turned everything off again, re-seated the power cord on my C2300, and tried again: only hum from the right speaker (unless I engaged the Mono switch). Finally, I tried playing a CD and had no problem. So it appears to be something specific to the TT setup, which hadn't been touched for months, except to turn on the TT now and then.

I thought I'd run this by the forum before being too quick perhaps to replace the tonearm cable (it's an SME 309 arm). If there's something I haven't tried yet that I've missed, perhaps someone here could point it out. Thanks. BTW, I did just think of cleaning the tonearm cable contacts; I will try that tomorrow.