AC30 Butt hurt

MikkiMcMurderer

Would any of you technically minded experts know why this weirdness is happening?

I turn on the amp and often there is no sound. If I put up the pre amp normal  volume to max you can here a tiny signal coming through and then all of sudden the it sometimes comes on full volume and then all is well while i'm playing. Until next time. It happens most times I turn it on.

I just revalved the whole amp with JJs but exactly the same thing happens.
Before I take it into a tech, any ideas of what it could be?

Cheers!

MtB

I've had something similar with my 5E3 self build, and the cure was spraying contact cleaner into all of the valve holder bases. Just a bad contact - doesn't do it any more.

MikkiMcMurderer

Hmm - good tip thank you I'll try that...

PSR

Often get the same thing from a worn pot. 

Strat_a_tat_tat

PSR said:

Often get the same thing from a worn pot. 

Would switch cleaner help there too... if it's just dust and general crap?

ICBM

Which model of AC30?

It does sound like a bad contact somewhere in the signal path, but it would be useful to know which model to try to work out where it might be, as some of them are quite different.

MikkiMcMurderer

Hey ICBM!
Its the Custom Classic CC2 - the one from 2005 with alnico blues

ICBM

OK… if it affects both channels it has to be something from the FX loop/reverb/master volume area or later.

Does it do it if the FX loop is bypassed?

When it's 'quiet', can you hear any hiss through the speakers, or does that only come on when it's 'working'?

DJH83004

Another simple thing to look at, on the CC2 there are a number of ribbon cable connectors between the controls on the top plate and the main board which are in the signal path, it is worth just taking them in and out, in case it is a bad connection. Also you don't make mention of the top boost input - is that working OK or the same as the normal input?  

ecc83

Int' bad connection in the speaker circuit?

Dave.

thecolourbox

How long is it before the sound starts?

Cirrus

Ah, if it's a CC my first check would be the FX loop bypass slider switch. ICBM is on point. Again. I had this happen to mine once.

Of course, it could be something totally different, but it's a start.

Teacherphil

I had an issue with the channel blend switch. I swapped it out ( a bit of a pain in the arse) now works fine. Wiggle the switch and the jack sockets around a bit, see if it's that.

Teacherphil

Mine was an AC30CC1

MikkiMcMurderer

Hi guys I think it was the fx switch bypass I gave it a good wiggle and contact cleaner squirt! Thanks chaps!