drew82

Hey, I've got a Marshall DSL50 amp head that I have owned for about 2 years now, and I haven't changed the tubes on it since I bought it. It has worked perfectly and sounded beautiful in all of that time. Two weeks ago I set it up at an outdoor gig in Miami, FL, and found that the second channel (ultra gain) was not working at all. Channel A works perfectly, but I don't even get a faint sound when I switch channels. Any ideas on what might be going on? It was really humid at this gig (go figure, it's Miami), and the trailer we haul all of our equipment in shredded a tire on the way down, so everything got bumped around for a few seconds, but nothing was visibly damaged, and no other equipment experienced problems.

RachelMorgan

tube got knocked a little loose?

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poeman33

Have you checked to see that all the tubes are glowing when it's on? Maybe it's just one tube that was broken or is loose.

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Marshall JCM2000 DSL50
Avatar Vintage 4x12 cab
Fender American Deluxe HSS Strat Ash body

drew82

Thanks for the replies, I'm hoping it's just a loose tube or something like that. Unfortunately I can't really turn it on and let it warm up right now because I only have the head with me, my cab is in another city (long story). I will check that out this weekend, when all the parts of my amp rig are reunited. If it is a loose tube, I assume it wouldn't glow like the others, correct? This may seem like a stupid question, but if it's loose, what's the best way to fix it, remove it and re-seat it? Is there any special way to do that, or do you just pull it out and push it back on? Sorry for all the noob questions, I'm just trying to learn more about my equipment rather than taking it to the shop every time there's a little glitch. Thanks for your help!

drew82

Oh, I should also mention that I opened the back of the amp up and looked at the tubes, and none of them is broken (at least, not obviously).

Adwex

You can turn the amp on in standby without a speaker load, just keep it in standby. You should be able to see all the tubes' heater elements glowing.

I wouldn't suspect a "loose tube", those tube sockets are designed to hold the pins firmly so that they make good electrical contact. I doubt anything is loose.

On the other hand, a tube certainly could have been damaged internally if it got knocked around, they're not exactly rugged devices.

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drew82

Okay, I just turned on the amp and left it in standby for about 5 minutes. All 5 of the tubes are glowing. Does this rule out tube failure?

Adwex

Certainly not, the troubleshooting continues....

Wait for the cab to return.

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