A few years back, my dad bought an early 70's Fender Twin Reverb (silver face, but before the master volume). And for awhile, it sounded great, till some issues made themselves noticed. Several repair guys couldn't fix it.

1. This is the main problem. The bass will randomly drop out sometimes, and I hafta hit it to get it to work again. I can get the same sound by turning the bass knob all the way down. The twin doesn't hafta be on for more than a few minutes for this problem to happen. And I know its the amp and not my rig. It'll sometimes go a month without this problem tho.

2. The reverb buzzes. One repair guy said he replaced it, not sure.

3. Normal channel doesn't work great. tone sux and its not as loud. Doesn't bother me, I always use the vibrato channel.

anyone know whats wrong with it?

guaranteed this guy can...check the client list...have taken my amp to him on several occasions and it always sounds better than ever

http://unclealberts.com/

Re: losing bass... If all the tubes are good, and the techs did a cap job, it sounds to me like there is a parasitic oscillation. Some of the changes in production methods when Fender switched to silverface could cause this to happen if the amp was modified to blackface specs.

I had a late 70's Pro that I did a Torres mod on (yeah, I know...) and it exhibited the same problem you describe. I have a book by Gerald Weber that describes this symptom and says it is likely a parasitic oscillation. I will try and dig it up and get back to you. It has been a while since I read it.

If you've got a piece of gear that responds to percussive maintenance then you have a normal mechanical problem. Most common thing in the industry. Something's come unstuck. In your case, maybe a faulty solder joint or more likely a loose rivet on a lug on the bass pot. Could be any number of other things but it will be a bad connection.

Reverbs shouldn't buzz, either a bad ground, the wires to the pan are backward, the footswitch is connected wrong, or a bad pan are your most likely.

Normal channel just isn't the same. It has one less gain stage. Might want to just swap the first two preamp tubes to see if that's it.

Wouldn't be a bad idea to just check it in and have it gone over. Probably need to find someone a little more knowledgeable than your last guy.

If you want to attract attention to an older thread, please just post to it again to "bump" it. That way people don't have to go looking for it.

thanks for the help guys, but in addition to all of these other problems, a speaker cone tore. and rather than fix all of these problems now, i'm probably just gonna get a new reliable amp, and then when money is in again is when i'll worry about fixin it. by the way, any good speaker suggestions?

A 70s Twin in properly maintained condition is probably the most reliable piece of equipment on the planet. You'll pay more for something new than making this one great.

Ron

I agree. There's more 30- and 40-year-old silver and black-front fender amps out there for a reason. They were made to last. And I've seen plenty with original tubes and caps. Get that amp fixed and serviced with fresh tubes and caps, get a grounded power cable, and it will serve you faithfully for many more years.

Got a grounded cable. I've had the reverb tank replaced once. Had ever solder joint looked over. Retubed. Fuse replaced. And it still has the main problems. On top of needing to get a new set of speakers. If anyone knows a really good tube amp repair guy in the Atlanta area, then that's different. But no one i've taken it to can fix it. I almost cried when the speaker blew.