Argh... there is a strange noise from my new Fender 65PRRI: while fretting a high „f“ on the G- or the D-string a strange and short „groan“ or „pant“ appears, dunno how to describe. „Hisss“ or „Shhhh“... Sometimes on other notes. I‘ve changed all of the preamp tubes but it didn‘t solve the problem. Can‘t imagine it‘s a prob from the Power Tubes. No fun to play the amp with this noise... Any help is greatly appreciated!