Bah amp troubles....

[Mllerrin]

So I go to play my mesa and right off the bat I notice some wierd stuff:

Well number one with my volume and tone on 10 I strummed a chord and no noise.
I check and make sure my cables are all connected and stuff no problem there.
So I step on my footswitch, but the amp stays on the clean channel, and I get a slight buzzing, no noise when played.
I step on it again and it goes to Distortion Channel 2, but no noise and the buzzing is louder.
This is the really wierd part. I go back to the clean channel, and mess with the volume knob. When I put the volume down to about 4 or 3 the amp switches to Distortion Channel 2!

I've never heard of anything like this. I'm guessing it has to do with the guitar but can someone help me?

[Paul S.]

Re: Bah amp troubles....

You didn't say which Mesa it is, but I'll take a guess... I've owned a bunch of Mesa amps, and one thing that they all had in common was that they behaved very strangely whenever there was a tube problem - especially the TriAxis.
I would try replacing all of the tubes to see if it helps. If not, call Tien at Mesa and I'm sure that he can help you out, if you can get a hold of him.

Good luck,
Paul

[Mllerrin]

Re: Bah amp troubles....

It's a single rectifier series 1. I was thinking about replacing the tubes anyway. I thought it might be because a couple of times I was bad and turned the standby off to unplug the cable from the amp (what you're not supposed to do) to use my tuner (really need a tuner pedal).

Thanks i'll look into new tubes.

[Robert S.]

Re: Bah amp troubles....

The single most common problem with tube amps is tubes that are bad.

Mesa amps use tip-ground switching. You can make them switch channels by simply inserting a shorted 1/4" jack into the switch jack. I'm not sure why your amp is channel switching from the guitars volume control because the signal path is not common to the switching circuit other than the fact that they use the same ground path. The only guess I can make is that a bad tube is corrupting your ground path and that could mess up your switching and add a lot of noise.

Check out the JJ tubes and Bob at Eurotubes.com. I placed an order for tubes last sunday with Bob and they arrived on tuesday. I installed a total of 16 tubes into my Mesa Triaxis/2:90 rig and the improvement in tone was staggering. Tighter bottom end, nice round mids and a less harsh, more singing top end were just some of the improvements. My clean channels are now fat and round and the gain channels smoothed out and nasty. The Sovtek tubes Mesa uses don't do their amps justice. JJs are killer in those amps.

[benjaturner]

Re: Bah amp troubles....

So the amp powers up but there's no signal coming through at all? Dude, check your fuses. Erm... apart from that I don't know, but I can't figure how a bad valve would hijack the channel switching. Weird! Sounds like you might have high rated fuses and a componant has died in your amp. I can only guess that there's a physical problem with the amps circuit to induce this sort of behaviour. Open the amp up and if something has blown you'll probably be able to smell it. If not then have a quick look around and check the fuses. I think there'll be one in the standby signal, this is the one I think has maybe blown. Failing this I'm completely lost. Weird stuff going on, maybe you've just got ghosts.

[FireBros.]

Re: Bah amp troubles....

IIRC those amps use LDR's (light dependent resistors) for channel switching. Mesa is phaseing those out of their amp designs, because they were getting a lot that didn't pass QC, and some that were unreliable. Try the tube change first, because that is the most common problem with any tube amp, if that doesn't fix the problem, call Mesa. They have always been very helpful, with helping me troubleshoot a sick amp.

[Mllerrin]

Re: Bah amp troubles....

Thank you, just confirming um I should get the JJ6l6's right and not the el34's?