Amp volume keeps cutting out.

[aandres17]

Hey guys,
I recently purchased a new Mesa/Boogie Rect-o-verb combo a few months ago and it's been working until a couple weeks ago. Now, about 10-30 minutes into playing, at bedroom volumes, the amp would get really loud with lots of static for about a second then the volume would cut out completely. I’ve never had this problem with my old amp (F-30) and I’ve tried moving the amp around using different outlets but it keeps happening. Do any of you guys have any idea what is going on? Any help would be greatly appreciated. Thanks.

 

[clutch71]

Volume swell is usually a product of the power tubes. I'd start there are the power tubes are warrantied for 6 months.

Static is usually a by product of a bad preamp tube or scratchy pot. If the outlets you tried were on the same circuit, that could have been the problem. There's a lot of variables there.

 

[BobL]

The problem you describe is generally associated with a preamp tube, but could also be a bad output tube as well. Pick up a cheap 12AX7 at GC or any music store and replace each preamp tube one at a time starting with V1. Run the amp and see if the problem goes away. If not shut down the amp, replace V1 with the original and then move to V2. Follow this procedure until you have checked all of the preamp tubes. If the problem goes away then call Mesa and they will replace the tube for you.

If you feel it may be A/C related you're headed in the wrong direction as far as your house circuits are concerned. To prove the point plug a lamp into the same outlet as the amp while you play. If the lamp goes out you have a problem.

Also, do not plug the amp into a surge protector. Quite often the breaker in a surge protector will overheat and shut down. I doubt this is the case here based on your description, but in any case don't use a surge protector.

Another problem could be the DC power supply filter capacitors. In this case if you don't find a preamp or output tube causing the problem call Mesa and arrange for service. Hope for the tube.