MP-1 just started squealing!!!!!

[h.e.l.shane]

My MP-1, 3.666 mod, just started squealing like a banshee with the guitar volume on 10 on most of my high gain presets.. turn the guitar volume back it stops (depending on the pickups, depends on how far ya gotta roll it off)

else,  you gotta lower the master gain and the OD2 to get it to stop squealing without lowering the volume knob on the guitar..

NOTHING had changed...  same guitars.. .same cables... same pedals... .same amp... same cab..


I tried swapping tubes, even putting a lower gain tube in.. swapping chords, etc.... no luck...  it seems to be related to the input signal...

and, being that it all of a sudden just started doing it..  I would suspect its a component crapping out...


Anybody have a clue what when south??  I saw reference to something similar for an MP2 on youtube, involving a resitor..... but not for an MP1

[GuitarBuilder]

This is a question for MarshallJMP.......

[MarshallJMP]

Maybe one the shielded wires on the tubeboard?

[h.e.l.shane]

Like one of the shields came loose???

I just got an MP2 of evilbay, when it gets here im going to pull the tube board out of this one and give it a resolder, possibly get another board

[rnolan]

Enjoy the MP2, bit of a different beast to the MP1  >:D , I did the transition as soon as the MP2s came out here (Australia), never looked back, until now I'm getting a little nostalgic for that great MP1 sound (and all the MP1 discussion here on the depot reminds me).  BTW, when your MP2 arrives, check that the compressor and wah work without issue (they are both before the tube stages in the signal chain and can cause no input to tubes if switched in and they have issues), I've never had any problem with either of my MP2s but others here have.

Good luck with the tube board, hope it solves the problem  :thumb-up: .

[Dna^Yay]

Is the squeal really high pitched? Not like feedback but something else as iv had the same issue. Cut all of my eq to zero and it can still happen, think it's something to do with od1, when I roll the guitar volume up sometimes it proper kicks in and sounds horrible.