Mesa Boogie Mark 5 : Twenty Five

[mikeydee77]

Anybody have a schematic for one of these? It's the compact little 2xEL84 head from 2017 in my case and with some strange signal problem that means it is outputting virtually nothing.

Thanks in advance.

[alexradium]

Anybody have a schematic for one of these? It's the compact little 2xEL84 head from 2017 in my case and with some strange signal problem that means it is outputting virtually nothing.

Thanks in advance.

try using the loop in and out to determine if the problem is the preamp or poweramp

[Chuck H]

I never have any luck tracking down modern schematics from the likes of Mesa. And Mesa schematics are prone to errors anyway (intentional or otherwise). I've read that Mesa isn't as accommodating as they use to be, but they use to be very accommodating. If normal maintenance things like cleaning contacts doesn't help you should call Mesa. It there's an inherent flaw that causes signal dropout with any regularity they'll know about it and likely tell you how to solve for it.

[mikeydee77]

Hi yes it is between effects return and PI grid. I suspect it is going to be a weird boogie thing like a pcb trace touching a resistor body. They seem to hunt me down.

[mikeydee77]

Hi Chuck I have requedted schematic from MB. I have had helpful info from them before but I think it is all down who handles your call or mail.

[g1]

Is this different from the Express 5:25 ?
https://music-electronics-forum.com/...2&d=1370648942