tube amp expert...advice needed.

[jimistone]

I have a fender hot rod deville that sounds like it cuts in and out of phase when I lightly run the pick accross the strings. When I bear down and pick hard it has a distorted crackle.

When I plug straight into "power amp in"....nothing changes, does the same thing. The amp will do this for about 30 minutes, then, after it has warmed up for half an hour...it sounds perfect and there are no more problems as long as I don't turn if off and let it cool down.

I gig with it so I just get to the club an hour early to turn it on....by the time I take the stage it sounds great and screams.
However, I know something is not right and would like to fix it if possible, before it goes out in the middle of a set.

So far I have changed the tubes (power and pre-amp) and soldered in new plate load resistors (all of them)
I have done some mods on it, but they were done after it started this crap....so the mods and my soldering are not the problem.
Any input would be appreciated guys.

 

[Thatupstateguy]

If you have changed your tubes several times,... or pulled them and put them back,.... the rocking motion needed to remove them,.. will loosen solder joints in the socket,.... they may look good, but......

at least that's my take on it,.... happened to me.....

Different amp, same problem.....

 

[jimistone]

If you have changed your tubes several times,... or pulled them and put them back,.... the rocking motion needed to remove them,.. will loosen solder joints in the socket,.... they may look good, but......

at least that's my take on it,.... happened to me.....

Different amp, same problem.....

Did you just resolder them...and it fixed the problem?

 

[jimistone]

I will try resoldering those joints....I hope it's a simple fix like that!

Thanks upstate, I really appreciate the reply.

I posted this problem in the fender forum too....alot of knowledgeable tube amp guys there.