Last night a squeal and an oscillation

basisfunction · Post by **basisfunction** » Wed Jun 06, 2007 12:01 pm

So last night I plugged in my Fender VI into my recently completed Metroamp 69 plexi. I turned up bass/mid/treble to 5-ish, and I turn up the bright channel volume and I hear an oscillation and squeal that disappeared/die out as I turn up. Amp seems fine after that. I cycled the standby switch and the squeal was still gone when the amp was on. Then when I turned off the amp I hear the squeal again as I turn off.

Any ideas?

NY Chief · Post by **NY Chief** » Wed Jun 06, 2007 3:39 pm

Is the amp in the head box? Some us get squeal when the chassis is out of the box. You also need the aluminum shielding plate under the chassis (stapled to the head box) to help.

basisfunction · Post by **basisfunction** » Wed Jun 06, 2007 4:36 pm

Its in the box, preamps are shielded, back cover is on.

I think the squel may indeed be microphonics, but they are incited somehow by the oscillation.

The oscillation and squeal fade out togther after a few seconds, after turning up the volume.