Ground buzz - Driving me crazy

[martin manning]

I've seen some guys use some kind of AC Filter build into the power socket in their amps. What is that for?

It's for reducing HF noise on the mains voltage. Your problem is LF, which could be filtered out, but then you would be filtering out some of the audio range. Noise of that type is best controlled by shielding or eliminating the source.

[Littlewyan]

Yeah I'll try and get there first next time so its only me set up and will see if it buzzes then. I think the buzz changes as I walk around. There is a flat upstairs so maybe its something in there.

[tubeswell]

did you try a different cable?

[Littlewyan]

Yes I did. No difference. Except I think if I use a really long cheap cable. I only say that because I'm sure when I plugged in the really long cheap cable I couldn't hear the interference anymore. But that cable tends to roll off a lot of high end.

[Littlewyan]

This happened again a few times on and off at practice but only for very short periods of time. This time it went away when I turned the volume down, but wouldn't go away when I had the volume turned up and I touched the strings or the jack socket. And when I say short periods of time I mean in the space of 30 seconds. Must be something getting turned on nearby. I did wonder if it was my synth player's Korg Minikorg but one time when it happened he wasn't touching it.

Also this was with my Marshall JTM50 and not the Express. Not a huge issue though as I only noticed it twice and like I said it was gone within 30 seconds and also it isn't anywhere near as loud as the actual guitar.