Tube Amp Troubles

It wasn't me!

Oh yes, really am suffering those again. The other night, while playing, it just kinda... stopped. The amp was still producing those faint noises that tell you it's on, but nothing when the guitar is played, not a sausage. First thought is that the power tubes might be gone, but has anyone any corrections before I go spring for new tubes?

Eoin Madsen

It wasn't me! wrote:

but has anyone any corrections before I go spring for new tubes?

Yeah, they're called valves.

The problem you describe is not characteristic of a typical power valve fault tbh - all power valves would have to fail simultaneously to kill the output completely. If you can still hear it going in and out of standby then the problem is most likely in the preamp. Was there any warning signs - crackly or intermittent pots for example?

It wasn't me!

I can't think of any to be honest. Was going along grand, high volume, around 9, then just stopped. Was quite odd, and couldn't figure it out. Ever experienced anything like this before or anything? I'd really rather not shell out lots of money I don't have on expensive repairs if it'd be avoidable.

david

Time to give Mr. Eurotube a buzz.

It wasn't me!

I have a Eurotubes tab open in the browser, but will it fix the problem?

david

Look at it this way, if you buy valves and they dont fix it (10% chance) the repair bill will be SIGNIFICANTLY less should it need a professional service if you provide your own valves

It wasn't me!

You make an interesting point mister Lee... Eurotubes doesn't seem to do 6550's though, and I really don't feel like re-biasing the ****er.

david

Email him and say you wanna retube you're mean ass mofo of a marshall JCM800 combo and he'll tell you all you need. He speaks the truth, and its daytime over there so youll get a speed reply

It wasn't me!

Never got a reply from the bastard before, but I'll give it a shot.

Eoin Madsen

Try Watford valves, they should do 6550s. But it's not the powervalves, and a repair does not require replacing them, so it's an unnecessary expense.

Swapping out the ECC83/12AX7s one by one with a spare to test if one of them has failed is the most logical way to proceed. If it's not the ECC83s then it's probably a fault with wiring or with the output transformer.

It wasn't me!

Is it going to be expensive? Because I'm broke.

david

Eurotubes will be a lot cheaper than watford, ~€60

Eoin Madsen

It wasn't me! wrote:

Is it going to be expensive? Because I'm broke.

Do you have a spare ECC83? Even in another amp?

Eoin Madsen

freakonaleashx wrote:

Eurotubes will be a lot cheaper than watford, ~€60

Which is lovely if you want a set of moderately well matched JJs.

It wasn't me!

Got me a spare ECC83, tried swapping it out of all the positions. Not good news gentlemen. What do I do now?

Eoin Madsen

Now you take it to an amp tech.

There's nothing else you can learn without opening it up, and what you stand to learn that way yourself is, imo, too limited to really offset the marginal risk of fatal electrocution.

It wasn't me!

Bollocks. Anyone got a good one they'd recommend who won't rip me off?

Steoob

are you sure its the amp? it could be a dodgy lead or guitar wiring..

Eoin Madsen

That kinda went without saying!

sock puppet

It wasn't me! wrote:

Bollocks. Anyone got a good one they'd recommend who won't rip me off?

I'm taking my amp to mark levins, alladins amps. I got his number in musician in town. They said he was good. I think his number is also in the sticky on guitar resources.

Eoin Madsen

Let us know how you get on with it. What the service is like, cost etc.

sock puppet

Will do. I dont know how long it will be before he's finished though. I just dropped it up today.

gotBass

Have you tried any of the following?


1 are the lights on when you kick in the main switch?

2 have you tried listening to a lineout etc, this will tell you whether you have a preamp problem or not, the cost difference between the valves for power amp and preamp is large enough

3 did the amp take any impacet or was exposed to any moisture

4 have you tried the speaker itself to see if it works?

It wasn't me!

1. The lights work.
2. Nay, there's no buzz from the lead without the guitar connected, but it stopped working while I was playing, and that hasn't happened before when teh elad was the problem, so I'm inclined to think it's the amp.
3. No impacts or moisture of any kind.
4. No, have nothing else to power it with, nor the ability to confidently dick around with a rather old amp.

I'll see how the thread goes and then bring my amp to a tech if necessary. Poor baby wouldn't be getting enough attention for the next while anyway with school starting again tomorrow.