Mesa Walkabout Power Amp Section is Distorting

[Boneless]

Thanks for the reply. Would non Mesa service centres be able to get schematics to the WA ?

I don't know about that, *usually* companies tend to provide schematics to service centres, even not authorised service centres, for products that have (long) been discontinued. The worst case scenario is that you have to fit in a new power amp, maybe a different design that makes use of the same supply voltages and can be made to work with the existing thermal management. Any *competent* tech can do this (even experienced DIYers with a modicum of measurement tools can do this - audio tech is not rocket science, the hard part is not in making one-offs, it's in designing stuff that can reliably work over an entire full-scale production line).

 

[jnewmark]

So I'm not understanding something. You say you went out the Preamp into a power amp with no problems, and it sounded even better? Why not keep doing that, if you like it so much?

 

[David Morison]

1: if they're gigging out they may not want to carry the extra gear;
2: as agedhorse mentioned, whatever fault it has could be causing (or, a symptom of) other issues eg overheating, overloading the power supply, so best to get it checked out properly.

 

[agedhorse]

I had a similar problem with distortion. Turns out the B side of the AB amp wasn’t working. This was quite some time ago so I don’t remember the cause or repair cost. I don’t remember it being incredibly expensive. I would get it fixed though. I’m still using the amp for band practice and it still sounds amazing.

This makes no sense.

 

[agedhorse]

View attachment 7047128

This is who I recommend as a first step.

 

[bass_69]

So I'm not understanding something. You say you went out the Preamp into a power amp with no problems, and it sounded even better? Why not keep doing that, if you like it so much?

I may just keep using the WA as a preamp. The problem is that the power usage may be high as the power amp in the WA is still being powered.

As for posting the WA off to a service centre, I suspect it will cost a lot of money for them to diagnose the problem to find out that I have to pay a lot of money if it can be fixed.. Maybe more than the amp is worth.

 

[agedhorse]

It’s more the issue of continuing failure becoming catastrophic.

 

[HotelX]

This makes no sense.

Sorry I’m a dummy about this stuff. I’ll shut up now