Blues Amp
Restoration Project Diary
1960's
Fender Super Reverb Model AB763
PAGE 1 of 3
There is no other amp that has made it's mark on blues and rock and roll history like the Fender blackface Super Reverb. This amp and it's smaller brother the Deluxe Reverb are perhaps the most highly used and sought after vintage amps ever made. They were the natural evolution from the earlier tweed models and sported improved power and features such as reverb, multiple channels and instruments and a vibrato or tremelo effect as well. Even today when you visit a great blues festival you'll see these model amps being loaded and unloaded on and off the stage as each band or act sets up. In many cases a house band will set up their amps and everyone at the festival or event will play the same set of Fender amps on stage. There's nothing that sounds better for blues.
Hear an mp3 audio recording of the completed amp on page 2
This story starts many decades ago when the Royal Peacock nightclub in Atlanta Ga was still a famous blues club. It's located on the famous Auburn Avenue which is the black Mecca of the USA and the home of some of the greatest blues shows of all times. All of the stars played there in the day and even into the 60's and 70s. In the late 80s it became a Raggae club and the house stage equipment was sold off. Part of the deal was two Fender amps including the one shown here and an old piano. They were sold to a new blues club opening up called "Fat Matt's Rib Shack" which is now world famous. The piano still remains on stage at Matt's even today but the amps were trashed in a matter of 5 years from abuse 7 nights week. Rather than watch these old amps get thrown away I tossed the Super Reverb in my attic for almost 15 years and just now dragged it out for restoration. I'll share this process with you by posting photos and a diary. For you amp lovers out there this could be interesting.
Special thanks to the kind members on the FDP Fender Forum for helping me with great advice during my troubleshooting phases of this restoration. The big lesson I learned was to re-cap an amp this old with new electrolytic capacitors before you power it on or you could fry the transformers. See photos at bottom.
FDP Warning: If you wonder why I'm not an FDP member any longer it's because the non Fender associated owner of the site Chris Greene from Idaho is an irrational, unethical and raving lunatic. Go there, post, but stay clear of that monumental moron. Never paypal donate to that forum or you are subject to getting ripped off like me and others.
Above is the bare bones and remains of this great amp. I was actually shocked and had doubts whether it could really be rescued but I forged ahead like the stubborn fool that I am.
The label says this is an AB-763 model amplifier which is the most desirable era. The only thing Fender did wrong was sell out to CBS around 1967 and this model had a cheap particle board speaker baffle you can see here. I found almost all of the handles and other hardware in the wreckage. The speakers were long gone and honestly I had no interest in reconing them.
The other crime Fender CBS began was the use of these ugly ass modern silver faceplates and on this year model I was lucky the differences were only minor cosmetics and did not affect the operation of the amp. It also had a mixture of knobs and you can bet many of these components are bad or aged to the point of needing replacements. The beauty is the handwired fiberboard used. If you can repair these style amps they will last literally 100 years. They don't make em like this any more.
Above is the old power transformer which needs to be replaced. I'll keep it and have it rewound in the future and possibly reinstall it into the amp. For now this one will be replaced with a replica which are extremely high quality parts being made today to the exact Fender specs and alloys. Notice the old paper covered Mallory capacitor. Those two resistors soldered to the light bulb socket are not part of the design. No idea what someone was doing on that modification but it will get removed.
All of the volume and tone controls are filthy and will need serious cleaning before they can be salvaged and I don't know how many of them will be good enough to stay. The jacks are also filthy.
Above you can see someone has grey duct tape around the optic transducer than makes the vibrato/tremelo sound and just to the right is a capactor someone replaced that has gone so bad the end toward the top just burst out. In fact there's been a lot of shoddy repairs and workmanship and I'll have a big job on my hands cleaning up this whole board. The blue mallory caps to the right are original parts. The wiring is the old cloth covered stuff with a solid core. Non stranded and what I like.
The work begins and I removed the baffle to see if it can be saved with a recovering and removal of the ugly ass aluminum trim.
The whole baffle board is warped above and can never be used. This was the beginning of an era when Fender would innovate these amps to the point they were total pieces of crap in the 1970s era.
All of my new parts are beginning to arrive. I'll be restoring this amp to better than original condition because I'm installing a replica black faceplate and all of the true blackface components that Fender should have just left alone in this 1967 model amp. Mojo Musical Supply and a number of other companies specialize in making exact replica parts for old amp restorations. This was not the case years ago. I was even able to get speakers that are identical to the originals.
I'm having my 20 year old son do all the work while I bark orders. He loves guitars and amps so this is his boot camp. He's bolting in a new replica transformer that supplies AC power to the rectifier and all circuits.
The transformer is installed but we also installed a new 3 prong modern AC power cable and soldered it's (green) ground wire to the chassis lug. With my help I think he did a great job.
Also installed a new fuse holder and main AC power switch for added safety. I don't want to worry when this amp is left plugged in at a club or my home.
Installed the new black replica faceplate and then buffed it with 0000 steel wool then banged it up a little to look exactly like an old one would from decades of use. I even used the old screws. I also installed true replica knobs and aged them by buffing off the shine. I'll go back later and age the face plate color with a tint too. The amp is already looking more like an authentic blackface.
Making some progress with the amp looking better and the cabinet completely cleaned inside and out with a scrub brush and auto tire cleaner.
I'm going to save this hardware and use most of it because I'm not wanting a brand new looking amp. I want it to be a very solid player that looks like it has some soul. I'll scrub the rust off with steel wool and a solution of WD-40 which neutralizes the corrosion and makes the parts usable again.
Above I soldered up the replica braided wires for the reverb tank and fitting it into place to see how it looks. It feels so good to be getting this amp back together again!
I soldered up the cloth braided replica speaker wiring harness. It even has the little plastic Fender cap for the plug. The terminal board shown to the left is an exact replica and I'm very pleased with the quality of the mojo parts.
My son Josh finished installing the Jensen P-10R replica speakers and has the cabinet completely wired and ready. The nice new baffle board is very flat and true so the speakers will have a great foundation. It's also wood to wood contact from the baffle board to the chassis.
I began the process of replacing the worst capacitors but to be honest I'm not happy with these huge black T.A.D. (Tube Amp Doctor) brand capacitors. I think I may order the smaller sized equivalents. You have to group several pairs of these together as seen on the right and these are just too big. In the mean time I'll suck all the solder out of the 150-200 solder connections in the amp and rework them with less solder and much better long term reliability and TONE!
I also installed new ceramic super high quality tube sockets that will greatly increase the reliability and connections for the tubes. They fit very tightly into the new sockets. I also installed new resistors to the exact factory specs. The green pair of wires is the pilot voltage that keeps all the tubes warm and lit up. That's the light you see when you look at the tubes.
Above is a part of the amp most people miss. It's the main filter capacitor board underneath and hidden by a metal cover. These work like huge electric storage tanks that smooth out the voltage going to all the tubes in the amp. These are voltages that can kill you at over 400 volts. If you don't replace these caps and one happens to short out it will burn up your transformers and cost more money to repair than you can justify for most amps. Although these test out okay with my multimeter I don't trust them. These will get replaced before the amp is ever powered on again.
This is the new set of Sprague Atoms we installed. I did a really tight and neat job and every solder joint was cleaned and reworked from scratch. I then ohmed out all the connections and made sure I did not measure any shorts to the high voltage wires going up into the amp. Notice all 4 of the caps to the left are polarized with the positive going one way then the last cap to the right is turned the other way. These are the kinds of details that you can miss and blow the whole amp up and start all over again. I replaced the three 20uf 500v caps with I believe 22u/500 and then the two big 70uf 350v caps were replaced with 80uf/500 caps. This was as close as I could get and the experts at the Fender amp forum helped approve this choice for me. I got those from TubesAndMore.com
