Fender Deluxe Reverb Repairs
- Thread starter JRUBIN
- Start date
bob smog
Creebling at the Turntables
Nice vid. I've spend many an hour inside of my blackface deluxe.
Mine had a blown grid stopper when I got it, so maybe this was a common issue. Because of the blown resistor, I was able to buy it from a pawn shop for $20 (back in 1985)
On yours, maybe the repair person used a higher wattage resistor because that's what was in the parts bin.
Mine had a blown grid stopper when I got it, so maybe this was a common issue. Because of the blown resistor, I was able to buy it from a pawn shop for $20 (back in 1985)
On yours, maybe the repair person used a higher wattage resistor because that's what was in the parts bin.
drew_t
Well-Known Member
Boy, that's a super clean old Deluxe Reverb. Must have had an easy life somewhere; what is known of its history?
Doug Hoffman's guide to servicing Fender amps is a good resource for working on these units.
Doug Hoffman's guide to servicing Fender amps is a good resource for working on these units.
Ahhh, but there is no magical sound from carbon composite resistors except on the plate resistors, and even then it isn't much. Just guitar mythology that won't die.
The varistor effect of CC only shows up with voltage swings of a few hundred volts, because it's about 8% at the high end. Constant voltage just gives you a poor quality (out of tolerance) resistor that's a bit lower than it should be at that voltage. R.G. Keen thoroughly and totally debunked the mojo here:
www.geofex.com/article_folders/carbon_comp/carboncomp.htm
CC resistors also have lots of waterfall noise and it doesn't make the amp sound good, just noisy.
Science!
I have rebuilt two Heathkit T4 Aural Signal tracers to test such a theory....
At best extremely subjective..... especially when Ive found that the noise perceived was in fact coming from a 12ax7 - and this was proven beyond a doubt from a tube swapout. My post shouldn't be taken out of context, I don't believe in Mojo. people want original parts, I want to see values on test equipment.
tube-a-lou
Addicted Member
Wow great video's and nice job on the amp, I'm glad all those Blue Mallory's caps were all
good they add the magic to those amps.
good they add the magic to those amps.
Mikerodrig27
Active Member
Wow! I know this thread is old but I just wanted to say thanks for posting these videos. I just picked up a 1965 Deluxe Reverb that is completely original. I am going to order some caps for it and then start checking things. I am going to replace the 470ohm resistors on top of the sockets and try to get them out of the way of the heat.
Getting the Premium caps:
https://www.amplifiedparts.com/products/cap-set-fender-deluxe-reverb-ab763-black-face
A couple of these in 470ohm:
https://www.amplifiedparts.com/products/resistors-2-watt-metal-oxide-power
The cord:
https://www.amplifiedparts.com/products/cord-power-18-awg-3-conductor-black-no-iec-8-feet
I noticed that the cap kit only comes with a 50uf (I assume it is for the bias) instead of a 100uf. If it bothers me I think I'll look source a 100uf.
I figured this is a good way to kick the project off. Then I can go through and start taking measurements on everything.
Getting the Premium caps:
https://www.amplifiedparts.com/products/cap-set-fender-deluxe-reverb-ab763-black-face
A couple of these in 470ohm:
https://www.amplifiedparts.com/products/resistors-2-watt-metal-oxide-power
The cord:
https://www.amplifiedparts.com/products/cord-power-18-awg-3-conductor-black-no-iec-8-feet
I noticed that the cap kit only comes with a 50uf (I assume it is for the bias) instead of a 100uf. If it bothers me I think I'll look source a 100uf.
I figured this is a good way to kick the project off. Then I can go through and start taking measurements on everything.
My 1968 DR. 
Mikerodrig27
Active Member
Nice, here is mine. The only thing I've done to it so far is reflowed if you solder joints.
I got the amp by itself and put it in my Deluxe Reverb reissue cabinet. I have the original Reverb tank as well and the footswitch. I am going to build a separate cabinet for it and then put the reissue back together
I got the amp by itself and put it in my Deluxe Reverb reissue cabinet. I have the original Reverb tank as well and the footswitch. I am going to build a separate cabinet for it and then put the reissue back together
Attachments
As far as I know, the only circuitry difference between the original blackface and later silverface Deluxe Reverbs, is that crazy 1200 pico-farad disc cap in the output stage. Easily removed. 
http://ampwares.com/schematics/deluxe_reverb_ab763.pdf
http://ampwares.com/schematics/deluxereverb_ab868.pdf
http://ampwares.com/schematics/deluxe_reverb_ab763.pdf
http://ampwares.com/schematics/deluxereverb_ab868.pdf
Mikerodrig27
Active Member
That is what I have read. The silver faces are great amps. Heck, the new green board ones are great as well... Those are actually different though.
Yes, those two are very close. More changes came in the '70-'77 A1270 Silverface, like phase inverter grid leak resistors dropped from 1M to 330k. That change is also penciled in in the AB868 schematic. So that is one thing I checked in mine. I have circled the 1M resistors in the picture in post #14 above.As far as I know, the only circuitry difference between the original blackface and later silverface Deluxe Reverbs, is that crazy 1200 pico-farad disc cap in the output stage. Easily removed.
http://ampwares.com/schematics/deluxe_reverb_ab763.pdf
http://ampwares.com/schematics/deluxereverb_ab868.pdf
Mine even has the blackface AB763 tube ID tag in the cabinet.
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Mikerodrig27
Active Member
I ended up going through it. I replaced the V2 plate load and slope 100k resistors, the V4 plate load resistors, all the caps with Sprague caps. upgraded the bias to 50uf, replaced the screen and grid stopper resistors, cleaned all the pots, and gave it a basic cleanup. I should replace the phase invertor resistors as the 82k is somewhere around 94k or so and the 100k is at 117k... That'll be on the next order. With all of that, the amp sounds great! Much better now and almost dead quiet at idle when set at around 4. Reverb still picks up a little hum from the transformer but it is very little.
The original reverb tank was a little mushy sounding so I used one out of my DRRI.
I forgot to mention that I bought the '65 with the cabinet MIA. The previous owner used it as a microphone amp... I want to build a cabinet for the '65. It will be a natural wood finish with dovetails etc. I had a cool idea for the front. The speaker baffle will mount through the front with 4 machine screws. I want to build a baffle with my WGS ET '65 and another baffle for two 10's to kind of replicate a Vibrolux Reverb. I want to mount a 1/4" jack directly to the baffle of each so I can use a double ended patch cord. All that would be needed to switch baffles would be removing 4 machine screws and unhooking a 1/4" jack.
I am also considering messing with the dimensions but and not likely to deviate from the stock dims as I know that would effect the sound.
I have also been looking into putting some 6l6 tubes in it with a bias set to maybe 32ma or so. Still figuring this one out. I might pick up some JJ's. Should be fun!
The original reverb tank was a little mushy sounding so I used one out of my DRRI.
I forgot to mention that I bought the '65 with the cabinet MIA. The previous owner used it as a microphone amp... I want to build a cabinet for the '65. It will be a natural wood finish with dovetails etc. I had a cool idea for the front. The speaker baffle will mount through the front with 4 machine screws. I want to build a baffle with my WGS ET '65 and another baffle for two 10's to kind of replicate a Vibrolux Reverb. I want to mount a 1/4" jack directly to the baffle of each so I can use a double ended patch cord. All that would be needed to switch baffles would be removing 4 machine screws and unhooking a 1/4" jack.
I am also considering messing with the dimensions but and not likely to deviate from the stock dims as I know that would effect the sound.
I have also been looking into putting some 6l6 tubes in it with a bias set to maybe 32ma or so. Still figuring this one out. I might pick up some JJ's. Should be fun!
