Fender amp has no more reverb...help

[whattaguy]

I have a Fender Custom Vibrolux Reverb amp that sounds unbelievable, but the reverb is gone. I believe that it is an all-tube circuitry amp, but I have no clue to which tube to replace or if it is, in fact, the tube. Can anyone help me out or point me to the right direction? I'd rather try myself before taking it to the shop since I am out of work right now...repairs aren't cheap. Thanks.

Here's a PDF of the schematics:
http://www.fender.com/support/amp_sc...Reverb_0A4.pdf

More info on my amp:
http://www.fender.com/products/searc...tno=0215100000

My only thought is that it was jolted in my move from Seattle to Chicago, or someone moved it not so carefully after the move.

Thanks again.

[Hard2Hear]

Affixed to the inside of the cabinet, from the back, should be a tube diagram. Every Fender Ive ever seen has this. Look for the 12AT7 tubes. The 12AX7 are the preamp tubes (and the tremelo and reverb recovery tubes). But a 12AT7 is your reverb driver, so check that first.

I *think its position v3 or v6 for that amp, but Im not sure.

H2H

[whattaguy]

Originally Posted by Hard2Hear

Affixed to the inside of the cabinet, from the back, should be a tube diagram. Every Fender Ive ever seen has this. Look for the 12AT7 tubes. The 12AX7 are the preamp tubes (and the tremelo and reverb recovery tubes). But a 12AT7 is your reverb driver, so check that first.

I *think its position v3 or v6 for that amp, but Im not sure.

H2H

I pulled out the 12AT7 tube, but don't know what I'm looking for, honestly. It looks fine...meaning that I couldn't see any burned out filaments or anything. BTW, you were right on...it was the v6 position.

Should I be checking out the other tubes as well? Could it be another issue besides the tube?

Thanks.

[ggunn]

Originally Posted by whattaguy

I pulled out the 12AT7 tube, but don't know what I'm looking for, honestly. It looks fine...meaning that I couldn't see any burned out filaments or anything. BTW, you were right on...it was the v6 position.

Should I be checking out the other tubes as well? Could it be another issue besides the tube?

Thanks.

In my experience, it's rarely the driver or receiver tube in the amp.

Do you have the reverb footswitch connected? Disconnect it. If the reverb comes back on, it's the switch.

It could also be the tank (spring unit). Here's something you can do to test it (check me on this one, Light):

Turn the reverb all the way down.

On the back of the amp, find the RCA connectors that go to and from the tank. Mark which is which (the words "INPUT" and "OUTPUT" will be stamped on the chassis right above them.

Unplug both cables. You did mark them, didn't you? You did turn the reverb all the way down, right?

Now get a regular RCA patch cable and use it to connect the input jack on the back of the amp to the output jack. Turn the amp on and play. Turn the reverb up VERY SLOWLY. Does the sound change, like getting louder and maybe a bit distorted? If so, the amp itself (tubes, etc.) is OK, and it's the tank.

Reverb tanks are easily gotten, fairly cheap, and very easy to replace. They are the weak link in Fender reverb amps; I've had several go out on me.

[whattaguy]

Originally Posted by ggunn

In my experience, it's rarely the driver or receiver tube in the amp.

Do you have the reverb footswitch connected? Disconnect it. If the reverb comes back on, it's the switch.

It could also be the tank (spring unit). Here's something you can do to test it (check me on this one, Light):

Turn the reverb all the way down.

On the back of the amp, find the RCA connectors that go to and from the tank. Mark which is which (the words "INPUT" and "OUTPUT" will be stamped on the chassis right above them.

Unplug both cables. You did mark them, didn't you? You did turn the reverb all the way down, right?

Now get a regular RCA patch cable and use it to connect the input jack on the back of the amp to the output jack. Turn the amp on and play. Turn the reverb up VERY SLOWLY. Does the sound change, like getting louder and maybe a bit distorted? If so, the amp itself (tubes, etc.) is OK, and it's the tank.

Reverb tanks are easily gotten, fairly cheap, and very easy to replace. They are the weak link in Fender reverb amps; I've had several go out on me.

Thanks...I'll have to try that. If it is the reverb tank, where do I get a replacement, how do I replace it, and how much do they cost?

Thanks, again.

[AlfredB]

stewmac.com should have them ... also ask over at the www.fenderforum.com ... excelent advice, as well

best of luck
alfred

[ggunn]

Originally Posted by whattaguy

Thanks...I'll have to try that. If it is the reverb tank, where do I get a replacement, how do I replace it, and how much do they cost?

Thanks, again.

http://www.ampwares.com/reverb.html

They're about 30 bucks. You just pull the old one out of the bottom of the amp (usually held in place by a couple of wood screws) and drop the new one in, move the cables, and you're done.

Check that footswitch first, though. Oh, and before you replace the tank, be sure and check the cables going to and from it; that's another possible point of failure.

[whattaguy]

Originally Posted by ggunn

http://www.ampwares.com/reverb.html

They're about 30 bucks. You just pull the old one out of the bottom of the amp (usually held in place by a couple of wood screws) and drop the new one in, move the cables, and you're done.

Check that footswitch first, though. Oh, and before you replace the tank, be sure and check the cables going to and from it; that's another possible point of failure.

Doh! I pressed my footswitch and "voila!" my reverb magically appeared!

Thanks for helping out a simpleton like me.