AmpTalk.com

[vegetoe01]

Right to the repair man it goes, although will have to wait 2 weeks till i can get the cash.
Just hope it's a simple problem that won't cost lots.

[MikeM]

Have you gotten your amp back yet? What was the problem?

[guitarjoem]

You mentioned you've already checked for scorching, but did you pull the circuit board? Check the underside of the circuit board around the 3 large blue filter caps. Not just the side visible in the picture. Yeah, I know, this will mean pulling all of the knobs off and unscrewing the nuts on all the jacks. Check for scorching and/or melted solder connections.

[vegetoe01]

Went into repair today, should be getting her back next week,or the week after. At the very worst it could be a design flaw, at the least just a broken power valve/bad solder.

[vegetoe01]

UPDATE

It's in repair at the moment, but the problem is quite a weird one.
The amp tech explained to fit in with European laws the solder they must not use led based solder...
Now this solder is hard to work with and crap, also he looked at the joins inside and he said the connection were terrible.
So he's going to re-solder all the connections in the amp with led based solder.
He also explained since it's a combo when in use, it gets a lot of vibrations, so that would explain the intermittent problems when turned up loud, the vibrations are shaking the bad connections.
The guy repairing it is taking his time fixing it, been about a month, if he hasn't fixed it by Friday I'm taking it else where.

[MikeM]

I'm not sure I agree with his diagnosis? There may be a couple of bad solder connections but the whole thing?
I may be wrong but I believe the Valve King is made in China? I'm sure the amps for Europe are sent right down the same line as the ones for North America.

How much do you trust this tech?

[vegetoe01]

Got the amp back, all the background noise like hissing/popping has totally gone but it still has the same problem!





Certainly not going back to that amp tech, although he only charged 50 quid for the soldering..

I'm really stumped by whats wrong with it....
The amp tech said he checked it for any problems inside like internal arching and bench tested it and the problem didn't arise.

Any one reckon it's just a bad power tube? Since it only fails at higher volumes after a good 10-15minutes of use....

[tw001_tw]

vegetoe01- Too bad the cat couldn't fix everything for you - at least its
better, right? A few things for you to consider
Earlier in the thread you said "Right one of the pre amp tubes is dodgy.."
and then you preplaced that preamp right? Does it still make the odd noise
when you tap on it? meaning to test the connection in the socket more then
the tube itself? And secondly, when the problem occurs (10-15 min. @ high
volume) have you looked at the tubes right when it happens as to see if one
or more are not too 'red' (red plating)? Does it happen on both channels?
(if so, then the issue is probably in the power stage - if it only happens on
one channel, then its probably in that channels preamp) Do you run effects
before the amp and/or in the effects loop? And if so, does the problem
occur if you are just using a guitar and the amp? Most all of this is not really
to diagnose the problem, just to help isolate what part of the amp is causing
the problem to narrow your search.
As far as the power tubes go, why don't you ask that amp tech if you could
leave a small deposit and see if he'll let you borrow a set of power tubes
for a day or 2? (as opposed to buying a new set just incase that isn't the problem)

[vegetoe01]