Amp took a spill, Now problems arise

[JayLock]

Yesterday night upon packing up my amp in the car with our band stuff, my Ampeg J-20 fell out of the car onto pavement upside down (on the handle on top) Today when I played around with it to see how it sounded I noticed the Hiss had increased significantly and there is a lot less punch to the sound. It's much muddier and flubs out more on the low end. I'm assuming the speaker is alright, except for the chance of the magnet getting shaken up, but does this most likely point to tube damage? The tubes that where stock aren't that great and I'm thinking that there is a chance this fall really messed them up. Any advice/idea of what the problem is?

[mbratch]

It's possibly one or more of the tubes. If you gig with a tube amp, I think it's a good idea to have at least one spare of each kind of tube on hand in case one toasts. Or if you want to diagnose a problem such as this one. :D

I would not rule out speaker damage until you clear up the tube question. The speaker damage would cause hiss, but it could cause low end buzzing, if you hear any of that. A muddier, flubbier sound, though, is more likely tube related.

Do a good inspection of the innards as well to ensure nothing's jarred loose.

[mike80]

Most likely a tube.

I had a buddy's band using my practice space and my amp for a while. My buddy ended up knocking my amp head off of the 4x12 and onto the floor. When I checked it out, there was no sound coming from it. I checked the tubes, and a couple of the preamp tubes were bad. Go figure, they were the most expensive ones I had too.

If you have some spare tubes, try swapping out the tubes and see if that helps.

[RussB]

re-seat all the tubes