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Hi,
I am new to this forum, so hello everybody.
I am currently trying to repair my Carvin XV-112E combo from 1989, that I didn't use for years since it was damaged during a fire in our apartment.
this is the schematic of the amp
this is the 1989 Carvin amp catalog, if you want to have a look at the amp.
As for my background, I am new to the technical side of tube amps, though I am using them for playing since many years. Of course I did a bit of research before attempting the repair and I am aware of the lethal voltages in tube amps and am trying my best to do this very carefully.
My first attempt at getting it back to work ended in smoke due to a shortened power tube, that caused a screen resistor to burn. However after reading up a bit and replacing three failed resistors it was basically working again, but there were still a few things to do:
The reverb needed to be reconnected, I wanted to replace the remaining two screen resistors so that they are all the same value and I wanted to add a bias control to allow for adjustment of the idle current, since this amp has a non-adjustable fixed Bias.
I did these changes last weekend, but sth. went wrong
The clean channel still works fine but the lead channels output is suddenly very low, with the gain and master cranked all the way up it's barely audible.
I must also confess, that I accidentally had the amp powered on without load for a few seconds
So my first question is: Is it possible that a broken output transformer only affects one channel? It seems unlikely to me, but as I am a noob that doesn't mean anything, so it would be nice if someone could set this straight.
If it's not the ot, I'd suspect the problem to be somewhere in the preamp sections. However any tips on how to find the problem would of course be appreciated.
Thanks for your time
Niko
I am new to this forum, so hello everybody.
I am currently trying to repair my Carvin XV-112E combo from 1989, that I didn't use for years since it was damaged during a fire in our apartment.
this is the schematic of the amp
this is the 1989 Carvin amp catalog, if you want to have a look at the amp.
As for my background, I am new to the technical side of tube amps, though I am using them for playing since many years. Of course I did a bit of research before attempting the repair and I am aware of the lethal voltages in tube amps and am trying my best to do this very carefully.
My first attempt at getting it back to work ended in smoke due to a shortened power tube, that caused a screen resistor to burn. However after reading up a bit and replacing three failed resistors it was basically working again, but there were still a few things to do:
The reverb needed to be reconnected, I wanted to replace the remaining two screen resistors so that they are all the same value and I wanted to add a bias control to allow for adjustment of the idle current, since this amp has a non-adjustable fixed Bias.
I did these changes last weekend, but sth. went wrong
The clean channel still works fine but the lead channels output is suddenly very low, with the gain and master cranked all the way up it's barely audible.
I must also confess, that I accidentally had the amp powered on without load for a few seconds
So my first question is: Is it possible that a broken output transformer only affects one channel? It seems unlikely to me, but as I am a noob that doesn't mean anything, so it would be nice if someone could set this straight.
If it's not the ot, I'd suspect the problem to be somewhere in the preamp sections. However any tips on how to find the problem would of course be appreciated.
Thanks for your time
Niko
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