Peavey 5150 trouble. Please Help!!!!!!!!!!!!!

[HOLLYWOODxGRIN]

Ok so, my 5150 all of a sudden lost alot of its volume. It has a hissing sound and doesnt put out enough volume. My friend has the same head and his was sounding alot louder with more bottom end. I know my power tubes are fine bc they had just been replaced. I think it might be my transformer but im not sure. Please help me out. Thanx.

[R.G.]

It's probably not your transformer. I don't know why people always want to believe it's their transformer, but that seems to be the case. Transformer failures are really fairly rare compared to other issues. Maybe it's like having your stomach hurt and deciding you're dying from a rare and deadly tropical disease. Possible, I guess, but more likely it was those leftover anchovy tacos.

There is a reason they put tubes in sockets. The first step in **every** tube amp repair is to suspect a bad tube and swap in known good ones. Only when you are pretty sure it's not a tube should you go to suspecting something else. Do some tube swapping first, from your complete set of known-good backup tubes that you keep for just such an emergency in case it happens on stage.

[Chuck H]

+1

If the amp is hissing (as you say) at it's usual level it's probably something in the signal chain reducing your volume. Tube substitution is a good start. Believe me, just because tubes are new doesn't mean they're good. In fact old tubes that are just tired are very likely to be functional while new tubes do sometimes fail a few hours out of the box due to some undetected flaw that got past the brief test and burn in process.

Are all the tubes lit? Do they look like they're lighting correctly or are any of them glowing orange on the outside of the metal elements? Did any event precede the failure? Does your guitar use active pickups and do you have fresh batteries (same goes for floor prdals)? Are there any functions on the amp that aren't working, channel switching, tone controls, etc?

Dirty jacks are a Peavey signature. Try plugging a jumper into the effects loop. Just in case the tube sockets or pins are oxidized try rocking the tubes gently in the sockets to detect intermittant contacts (use an dish towel for power tubes unless you like blisters).