1973 Fender Twin Reverb - modification to do with reverb driver???

[lockwoodman]

Hi there,
Bought a 72/73? Twin Reverb and and am trying to get the reverb fired up.

So far I have bought a new tank and tried plugging rca leads in both ways.
If it helps I got a crash sound when I moved the reverb tank.

I took a photo of what looks to be a modification. I can't find any other amps with this mod and am not sure why it was done.



I will see turn the amp on the see if I can see the reverb tube fire up.

Any help would be much appreciated,

Josh

[Chuck H]

Do you have any test equipment? DMM?

[lockwoodman]

Not yet, will get a multimeter when i get paid on Monday.
I'm thinking some of the smaller valves are around the wrong way. I want to take one out to read the writing on the back - how do they come out? Two phillips screws?

[Chuck H]

For one, you cannot install these tubes the wrong way in the socket. For another, those cans over the tubes get pushed up toward the chassis and twisted about 1/8" to uncover the tube. Then the tube can be removed by pulling while gently rocking in a circular motion.

You should probably let a qualified tech handle this one. It's probably not complicated as diagnostics and repairs go for a qualified shop but you are so absolutely uninformed that you may actually cause more damage. At the very least you'll spend far too much of your own time to make any saviings worth while.

If you want to get into amp repair and modification then go buy that multi meter and get a couple of books about tube guitar amps. We MAY be able to help you with this repair but it's going to be like trying to order a meal in country where yyou don't speak the language or recognize the food. This sort of thing is much easier when you know some basics. If your not into that then you really should just have the amp repaired.

[lockwoodman]

I am wanting to learn about this, but probably will end up taking it to someone else to fix this time.

[Fee]

I concur, it's also possible that you could be electrocuted by this amp, so it's best to start out slowly. Find a qualified tube amp tech in your area and ask him to help you with this amp and he may even help you learn about them, bribe him with coffee and treats. There are many books to help you and you will find that every one of them starts with a warning about being electrocuted if you don't know what you're doing. Be patient, learn slowly and safely, follow every precaution every time. After a while you'll be answering other people's questions and giving them the same warnings. Best wishes.....

[lockwoodman]

Thanks for the advice Fee, I know just the dude qualified. Hopefully I can watch him and learn.
I watched a video yesterday about draining capacitors - the guy used a alligator clip lead with a 470k resistor in between.
He clipped a chopstick on end and used it to touch all the positive ends. Then he went around with a multimeter and made sure they were all drained.

I have begun to read "Electrical Principles for the Electrical trades" which will provide me with a tonne of base knowledge. Also been reading a fair amount about fuzz pedal building.

I am real keen to learn and find it all exciting and interesting.

[Chuck H]

being able to manipulate your own sound at a deeper level than just turning a knob is VERY satisfying. Loads of fun ahead. Just don't do like many here and stop playing your guitar because you spend too much time playing with your amps (guilty).