Help! Bandmate ran amps in series and now one has volume problem.

[sflusch]

My bandmate ran my main and backup Epiphone Valve Jr. heads in series, and now the one that he had second in the series has very little volume & thin tone...

He claimed to be trying to get an overdriven sound out of them, so I'm guessing he plugged the lead head in, cranked it up, and used the second head to control the volume. I don't remember which ohm speaker output he used, but the difference between the heads is really noticeable.

Could he have blown one of the tubes? What would the effect of using the different ohm outputs (4, 8, and 16) have on the input jack of the now faulty amp?

Thanks!


Edit for clarification: Here was how I found the stack:

Guitar --------- Amp1 ---------- Amp2 --------- Speaker cab

Amp1's output was the speaker output, which ran into the input jack of Amp2.



Amp 2 is the one with the problems.

[Gtr_tech]

What likely happened was the output transformer of the first amp in the string was damaged along with the possibility of the output tube/socket damage. The first amp was effectively ran without a load....don't *ever* do that. The only exception to that would be if you used the correct value dummy load resistor in place of the speaker with a line out circuit added off the speaker output. You couldn't really run the full output from the speaker jack into another amps input without driving the first gain stage into cutoff.

The short answer.....just use a pedal in front of *one* of the amps.

[sflusch]

The amp that came first in the series is absolutely fine. It still sounds great, but it's the one that came second that has the issue.