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Fred Nachbaur
 
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timbo wrote:

Hi guys,

Dont know if this is the right group, but i'll try anyway -

got a carvin X-Amp model XV-112.
this thing is a hybrid valve/op-amp type thing (3x12AX7, 4xEL34) 100w
output. whenever you turn the gain (either the clean channel or the lead
channel) up past about 5, the amp lets out a really high pitched squeal &
any signal level (like a guitar input) drops out to almost nothing, so all
you hear is the squeal. if the eq is set with the highs boosted, it's much
worse..

anyone got any ideas what might be wrong with it? tried changing valves, but
that makes no difference..

cheers,

tc.
.


I would suspect filter capacitor problems (dried out, lost capacity).
You can temporarily bridge a known-good capacitor, say about 20 uF at
adequate voltage, across the existing ones, to see if that makes a
difference. If it does, replace them.

Cheers,
Fred
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