Mark III cutting in and out

[JiveTurkey]

jumper the loop with a straight cable as well. ive had two mesas that helped, but never a mark. my mark did that when my power tubes were about cooked.

I didn't think to pull the loop out of the equation. I should do that. I am kinda scared at this point to fire it up and blow the amp though. I might do a tube roll from the tubes in my V, then try removing the loop from the equation if it exhibits the same problem

 

[Boudoir Guitar]

I am kinda scared at this point to fire it up and blow the amp though.

Yeah, wait till T-giving so you'll at least give the fam the gift of Fried Turkey. (srsly though, mojo and crossed fingers on the amp. Ugh.)

 

[laxu]

I'd try running a modeler into the loop return to rule out the Mesa's preamp entirely. If it still fades, you can expect the issue to be the phase inverter or power tubes.

 

[JiveTurkey]

Yeah, wait till T-giving so you'll at least give the fam the gift of Fried Turkey. (srsly though, mojo and crossed fingers on the amp. Ugh.)

"Get your fix now on Thursday because Mom and Dad are going to Death Angel this weekend!"

I'd try running a modeler into the loop return to rule out the Mesa's preamp entirely. If it still fades, you can expect the issue to be the phase inverter or power tubes.

I have SO much gear at the house. All my "experiments" involve going nuts. I will set aside some specific time this weekend and see where I get with it. Power tube swap first as that is the scariest failure and then check the phase inverter after that.

 

[HotRats]

This sounds very similar to what I am experiencing with my Vypyr 60. It was playing fine for a bit then it started to intermittently fade out. Then it just stopped making sound. I suspected power tubes so I picked some up yesterday and put them in this morning. Played for about 30 minutes and everything seemed fine and then it just cut out again. Hope the power tubes is all your is. I seem to have something else going on.

Few months ago my mini jubilee started to loose volume and made strange noises.

The issue was causes by dying power tube.
I replaced both the el34 and the amp had similar, but not identical, symptoms after few minutes.

Turned out is was a power tube again.

So here's hope, man!!!

 

[EOengineer]

The super special silver lining here is that if this was a failing tube, you might not have heard this amp at its best yet.

I doubt it’s anything more than a tube or possibly even a dusty fx loop jack.

 

[JiveTurkey]

Swapped the 445 6l6s in from my Multiwatt and no volume issues. Going to put the old tubes back in and play for a few just to confirm.

 

[texhex]

Swapped the 445 6l6s in from my Multiwatt and no volume issues. Going to put the old tubes back in and play for a few just to confirm.

Keep an eye on the old tubes after you put them back in and start playing. That drop in volume can also be when a power tube starts to red plate and you wouldn’t want it to just runaway and totally burn.

New power tubes should sort you right out. Get the Mesa branded replacemnets, the are easy to use, sound great and take any guesswork out of the equation.