The Chetboard

All,

I'm stumped. I took my prized PRS acoustic guitar to the PRS factory last week to have an acoustic pickup installed. I got it home, plugged it in, and there was a noticeable hum coming from the amp, which went away if I touched either end of the guitar cord. I could also make the amp "crackle" by running my finger up and down the high E string. I figure the guitar isn't grounded properly, so I take it back to the factory, and they tell me they can't find anything wrong with it. So I take my guitar, amp, and cord to the local guitar store in the hopes of trying out other components to see what's wrong. I plug in my guitar with my amp and my cord at the guitar store, and it's dead quiet. No hum at all. And no crackle running my finger up and down the high E string.

So is it my house power that's not right? Keep in mind I have other acoustic guitars that I can plug in to the same amp with the same cord and there's no hum.

Like I said, I'm completely stumped. Can someone offer a suggestion to try?

Thanks,

Stan

Stan,
Have you tried another circuit in your home? You know...an outlet tied into a different breaker.
Have you tried another amp plugged into the same outlet?
grounded or ungrounded plug on the amp?

Amps are like cats. Always something unexpected. I had a Genz Benz acoustic one time and out of the blue it made this weird phaser sound and wouldn't stop, out of the left channel. Started to take it in a week later and it was back to normal.

Hopefully, someone will have had the same problem...or your amp will heal itself.

jay

I'm betting you don't have three prong wall plugs in your house.

Sounds to me like you have a grounding issue in your house circiut, Could just be your 'music room' plug which can be checked as Jay suggests by trying the amp in another room. If you're using a pedalboard of some sort you may be experiencing ground loop.

http://www.epanorama.net/documents/groundloop/

I do have three prong outlets at the house. Nice try, though. I took the guitar with me to perform at church this morning and it makes the same noise there. I don't think it's grounded properly.

I agree it's either a grounding problem or a shielding problem. Both generate a 60 Hz hum.

Call the PRS people.
It was their install that you paid for and it's clearly not working right. I have a feeling this issue has come up before and they should have some suggestions as to how to solve the problem.