diagnose my amp (please!)

bloomer

Hi all, my Cornell Romany plus is having a bit of a problem. When I turn it on, very often all I can hear through it when I play a note is what I can only think to describe as the reverb of the note. The note is extremely quiet and echoey. If I hit the strings hard it may bring the note to proper amplification momentarily, but that then cuts out and I'm left with the reverb portion. When the amp has been on for half an hour or so it sometimes starts behaving itself and it sounds as it should. If after working properly I turn it off and then back on immediately it usually works properly still. Any ideas would be very much appreciated!

jaytmon

Obvious question but have you tried a different lead? Or some switch cleaner in the jack sockets of both guitar/amp?

ICBM

Sounds like a fault in the reverb mixer section which is stopping the dry signal getting through. I don’t know anything about how the reverb is done in that amp, but if it’s like a Fender then it will be something like a broken solder joint rather than a valve.

DJH83004

As IC says, it sounds like you are losing the dry portion of the signal. When the fault is occurring, what happens when you turn the reverb fully down, do you lose the signal all together? 

Danny1969

That sounds like a bad joint to me .... basically a bad joint can act like a semiconductor ... open circuit until you hit the strings really hard and generate enough voltage for the bad joint to conduct. Then it stops conducting again. 

If it's got an effects loop like the custom has then put a lead between the send and return and see if anything changes

bloomer

thanks chaps, tried with reverb all the way down and problem persists, likewise with different lead and cleaner. I've been in touch with Dennis Cornell and he said if I post it to him he'll take a look, doesn't seem like the kind of thing I should try to tackle myself.