I have a Marshall avt150 head, last night I was playing it and it wa fine. I turned it off, ate dinner, and turned it back on.

When it came back on, the acoustic channel and the clean channel were fine but the 2 od channels are now playing at very low output even when turned up all the way.

Has anybody had a sinilar experience that might be able to help guide me thru fixing this thing?????

Moore433

Try checking out the 12ax7 tube your amp has,pull it out and do not touch the tube socket that is attach where the tube goes into your amp or you will get a big a hazardous electric shock.

Try using a new tube, if the problem is fixed then that was it, the tube you had gone bad.

If the problem persists let me tell you that it could be a potentiometer or cicuit that boost your amp´s volume (it once happened to our band with a Valstate older version), it is better to take it to Marshall tech repairman on a dealer store that have Marshall schematics.

Anyway good luck, those AVT amps are known as very reliable Road Warriors, so after fixing this you should be ok.
ROck on!