Question about VibroChamp OT wiring

[mort]

Recently I worked on someone's VibroChamp build that had never worked right. It ended up having a bad OT. The OT was a ClassicTone 18031 with taps for 4, 8, and 16 ohms and he had the 8 and 16 wired to individual jacks and the 4 ohm tap was wired to the nfb resistor.

With Fenders, I've only ever wired the output as stock, just exactly the way the schematic shows. Is it likely that his output wiring fried the OT or no? The symptom was low output and unpleasant distortion. I wired the original OT as stock and it still had the symptom. Wired in an identical OT as stock and full normal sound was achieved.

[g1]

Should not have caused a problem.
However, it would have been more prone to damage if run with no speaker connected. I don't think you could wire it up like it was using a shorting jack like the stock unit has. The shorting jack with the stock wiring protects it in the case of no load connected.

[mort]

It had shorting Cliff jacks which I got rid of and just wired it with one shorting switchcraft jack and didn't use the two other taps. I suppose if he had it powered up for long enough with two shorting jacks, one of them being shorted to ground the entire time it could still fry the OT?

[guitician]

I doubt that both jacks were wired to short, that would not make sense, unless that was done by mistake?

[g1]

Agree with above, with more than one jack wired for shorting, there would be very little output, as one of the unused jacks would still be shorted.
But, if the symptom of "low, distorted output" was very low, then perhaps it was run into a short, which could kill the OT if you tried long enough.

[mort]

I'm not 100% sure if they were both wired to short but in retrospect I think they were and it would have been done by mistake. The guy who originally built it was attempting his first build. I think somehow I overlooked the output jacks as a potential problem but had rewired it to the original layout anyway, but by then the OT was already fried. I'm just kinda looking back and wondering how it could have ended up with a bad OT this early in it's life. It's too late to know for sure but I think that's what happened...