Random high pitched sound

[jaketheripper]

Hi! So this just started yesterday. I was with my band, and one of us was talking so i turned my volume off from my guitar. Then the singer had idea for a guitar part, so i turned up my volume again. When i turned it up there was this really high pitched sound coming out of my amp so i rested my fingers on the strings. Now, every time i take my fingers off of the strings it starts up again.

Any ideas as to what the cause is?

 

[ManuelB]

accoustic feedback?!

 

[Sephael]

ground came loose somewhere i the guitar or your gear is plugged into multiple outlets

 

[GSingleton]

ground came loose somewhere i the guitar or your gear is plugged into multiple outlets

Def with bands or combos, if you all are sharing an outlet with too many plug ins...INSTABUZZZZZZZZZZZZZZZZZZ

 

[Mondo]

Do you use a lot of distortion?

 

[thedonal]

The amp's got tinnitus?

Hmm- sounds a bit like microphonic, but then you say it's only when you un-damp the strings. How loud is the amp? how loud is the high pitched sound?