Mark III cutting in and out

[JiveTurkey]

BOO!!! Will go along for a little clip then start to fade out substantially. Cables, speakers, pedalboard and guitar(s) are all good; it's something with the amp. Tubes maybe? Not a good development

 

[Nathan Explosion]

Try re-seating all the tubes. My 5150 did this a few times and re-seating the preamp tubes fixed it. I'm guessing the pins got a little oxidzed/corroded but don't know for sure what it was.

 

[RaceU4her]

i get anxiety literally every time i turn a tube amp waiting for the inevitable snap, crackle and pop! to happen. hopefully its just a tube

 

[JiveTurkey]

Try re-seating all the tubes. My 5150 did this a few times and re-seating the preamp tubes fixed it. I'm guessing the pins got a little oxidzed/corroded but don't know for sure what it was.

Fingers crossed it's something that basic! Its an old amp so could be a slippery slope

 

[DrewJD82]

My Legacy did that before a tube completely shit the bed and the amp stopped making sound entirely. Can't remember if it was a pre or power amp tube though.

 

[Mikael Dez]

 

[maggotspawn]

Power tubes.

 

[TubeStack]

9/10 times it's a tube, in my experience.

(That being said, having anxiety every time one turns a tube amp on seems extreme. )

Hope it's an easy fix, either way! Amp problems suck!

 

[JiveTurkey]

i get anxiety literally every time i turn a tube amp waiting for the inevitable snap, crackle and pop! to happen. hopefully its just a tube

None of them seemed loose but I haven't had a chance to fire it back up. I've got some spare power tubes in the Recto or the Mk V I can try and will probably go that route for my next troubleshooting step

My Legacy did that before a tube completely shit the bed and the amp stopped making sound entirely. Can't remember if it was a pre or power amp tube though.

I'm assuming power tubes? Fingers crossed it's just that!

9/10 times it's a tube, in my experience.

(That being said, having anxiety every time one turns a tube amp on seems extreme. )

Hope it's an easy fix, either way! Amp problems suck!

Considering the amps age; it could definitely be a few things. I hope it's something that simple!

 

[EOengineer]

Definitely would start with power tubes but given that amp’s age it should probably see a tech given some of the noise you’ve called out.

 

[Desertdweller]

BOO!!! Will go along for a little clip then start to fade out substantially. Cables, speakers, pedalboard and guitar(s) are all good; it's something with the amp. Tubes maybe? Not a good development

Probably a tube, if you have spares, check power tubes first as those generally fail more, then if that's not fixing it, 1 by 1 replace each preamp tube with a known good tube until the problem resolves. If it doesn't resolve by replacing tubes, take it to a tech. If you haven't done it already, Mark IIIs are all basically 30 years old (last known manufacture date was 1998) and I would recommend a re-cap. I recently had mine recapped and the difference was night and day.

 

[JiveTurkey]

Definitely would start with power tubes but given that amp’s age it should probably see a tech given some of the noise you’ve called out.

Probably a tube, if you have spares, check power tubes first as those generally fail more, then if that's not fixing it, 1 by 1 replace each preamp tube with a known good tube until the problem resolves. If it doesn't resolve by replacing tubes, take it to a tech. If you haven't done it already, Mark IIIs are all basically 30 years old (last known manufacture date was 1998) and I would recommend a re-cap. I recently had mine recapped and the difference was night and day.

The amp was gone through when the previous owner had it here a few months back at CME. Not sure their level of Mesa tech capability but I felt generally good about that statement nonetheless? I knew going in that there could be potential for issues given it's age. I LOVE the V. LOVE IT. But the III is some "barely more than a one-trick pony (in the best way possible)" and it really is something special. I can only imagine how a completely refreshed model would be.


I'm going to pull tubes from the V and do a little transplant work and go from there

 

[EOengineer]

The amp was gone through when the previous owner had it here a few months back at CME. Not sure their level of Mesa tech capability but I felt generally good about that statement nonetheless? I knew going in that there could be potential for issues given it's age. I LOVE the V. LOVE IT. But the III is some "barely more than a one-trick pony (in the best way possible)" and it really is something special. I can only imagine how a completely refreshed model would be.


I'm going to pull tubes from the V and do a little transplant work and go from there

Sorry, I don’t think I had that context. If it was serviced recently then I’d def chase the power tubes. Sounds like you’re on the right track.

It also wouldn’t hurt to roll a known good 12ax7 through each of your preamp tube locations. You could also connect a cable from the fx send to something with meters so you can verify signal is leaving the preamp - just an isolation test but might help answer some unknowns.

 

[deadpool_25]

BOO!!! Will go along for a little clip then start to fade out substantially. Cables, speakers, pedalboard and guitar(s) are all good; it's something with the amp. Tubes maybe? Not a good development

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.

 

[JiveTurkey]

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.

Mojo sent it's something simple. Ugh.

 

[EOengineer]

I doubt this helps, but I look at these tube amps sort of like relationships…if it’s special to you, maintenance becomes a necessary value add to keep the relationship going. It might hurt now, but then it’s back to 20 more years of killing the game on palm mutes.

 

[JiveTurkey]

I can only imagine what the III would sound like through a 4x12

 

[EOengineer]

I can only imagine what the III would sound like through a 4x12

WHAT ABOUT A 12x12!!!

 

[Boudoir Guitar]

WHAT ABOUT A 12x12!!!

It's like you've never heard of standing waves. 11x12 or 13 x 12, but never 12x12.

 

[newholland]

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.