Threshold SA3 buzz / hum in speakers


2004-01-09 4:17 am
Hi guys. I have an amp that will give off a bit of hum and buzz through the speakers regardless if there is a source connected to it or not. I have no special equipment except for a multimeter.

I measured the following at the loudspeaker terminals with no source.

LC - 0.06V AC, 0.18V DC
RC - 0.06V AC, 0.06V DC

The left channel does have roughly twice the audible buzzing and humming compared to the right. I took the amp to the shop and they said all checks out ok. I thought it might be some interference from something in the house so I powered off all other equipment or lights that I could think of but no change.

Is it possible that this is caused by some DC on my AC power line? I stuck my multimeter in the outlet and measured 116V AC but I also measured 17.4V DC. I'm guessing this should not be there.

Any suggestions welcome.