Blackface Super Reverb

Hand-wired Blackface Fender Super Reverb Clone Amplifier

Completely accurate vintage AB763 replica circuit

This amp started life as a bare aluminum chassis. Then I built it from the ground up using the finest NOS and vintage replica components available.

I'll start off describing how this project started. For over a year I began procuring the parts to build this amplifier. I got the vintage replica chassis from a seller on eBay who builds them in Thailand. Included were the exact replica turret boards for the main circuit, bias board, filter cap board, and the speaker distribution biscuit from this seller. The brass grounding buss was also provided from my Thai supplier. Every single component is EXACTLY the right spec from a blackface Fender Amp!

I began researching vintage Blackface Super Reverb amplifiers and sought every picture I could of every internal component, layout, cabinet construction, nut, bolt, screw, and lead dress to accurately replicate the Blackface circuit and avoid its many pitfalls such as parasitic oscillations. I got extensive advice from Gerald Weber of Kendrick Amplifiers and Vintage Guitar Magazine and Larry Rodgers of Rodgers Vintage Amplifiers to ensure I was on the right path. After a year of research and compiling data I began work on this project.

The most important component to get right was the cabinet. Many people like to use the cabinet made by Mojo Musical Supply. While it is a nice cabinet, it is not an exact replica - so I sought out Larry Rodgers to build me an exact replica Blackface Fender Super Reverb 4x10 combo Cabinet. He uses premium finger-jointed pine, with few or no knots. He uses the EXACT dimensions of his several Super Reverb amps to replicate the cab. The speaker cutouts are in the right place, and the baffle is a true floating baffle. Down to the tolex cut pattern, to the same glue, paint, and laquer, this is as close as you can get to a real cabinet. It has the correct glide feet and proper tilt back legs, and chassis straps and screws are correct too. Larry even included is a vintage style tube chart. In addition to the cabinet, I had Larry make me era correct set of front and rear plates for the chassis. EVERY detail has been paid attention to! I even have the correct Fender tail logo and aged grill cloth. I have fitted this amp with four Jensen AlNiCo P10R Speakers - the original Super Reverb speaker and benchmark all 4x10 combos are judged by.

Next I turned to the transformers. A long-time believer in Mercury Magnetics, I contacted Paul Patronete to ask his advice on which direction I should take with the transformers. I ended up buying a Tone Clone power and output transformer from Mercury to give me the most accurate voltages and output. For the choke and reverb transformer, I purchased vintage spec components from Hoffman Amplifers.

For the pots, wire, fuses, some switches, the vintage lamp, and tube sockets I purchased components from Ampwares. All tube sockets are phenolic. I wired all the tube heaters with 18 gauge solid conductor vintage cloth push-back wire. I wired the bulk of the amp with 22 gauge solid conductor vintage cloth push-back wire, with a few exceptions. I used 18 gauge stranded wire for the power supply from the tube rectifier all the way to the preamp supply. I tested and retested every component for value drift and used only the most accurate components. I used Sprague ATOM filter capacitors with vintage values and vintage spec metal oxide decoupling resistors. This circuit has the balancing resistors on the first filter stage that drains the filter caps when the amp is off - just like the originals. I used CTS plastic shaft pots throughout the amp, including the 10k bias pot. I used carbon composition resistors throughout the amp with the exception of the power and bias supply, and the screen grid resistors - for stability. For tone caps I used a combination of mostly SOZO and Mallory 150 series capacitors. The grounding capacitor is also a Mallory 150 series. The electrolytic capacitors are all Sprague ATOM with double the voltage rating - 50 volts - for longer life before replacement is necessary.

Now - for the really special part of this amp. For several key components I used old parts from original Fender amps I have owned. For the two sets of input jacks for each channel I used original jacks and 68k resistors from a '68 Bandmaster Reverb. I wired the inputs using shielded (grounded only at the input side) wire. The wire from the tone stack/volume control is also wired with shielded wire. The screws used to hold down the main turret board, filter cap board, and power supply filter cap board are all original screws from my 1968 Bandmaster Reverb. The filter supply cap can is an ORIGINAL cap can from my Bandmaster Reverb. This cap can is impossible to find after market. The new cans from fender have a stupid hole in them to feed the wires through the can because they do not use the original layout. This has an original cap cover to keep the authentic look. Next, the three position switch used to change the ground reference on the back of the amp is an original three position Carling Switch. Taken from a 1970 Fender Twin Reverb, this original switch fits properly in the space. New switches are too big and they interfere with the output tube sockets. The screws that attach the bright switch to the faceplate are also from my 1968 Bandmaster Reverb.

Because original Fender amps used ceramic disk capacitors, and new construction ceramic caps do not look or sound right, I raided several ceramic caps from the 1968 Bandmaster Reverb and the 1970 Twin reverb I own. All of the ceramic disc caps in the tone stack, reverb circuit, and vibrato circuit are old stock caps from real fender amps. I am also including six original J-slot tube shields for the preamp tubes from my 1968 Bandmaster Reverb.

All tubes I bought from Lord Valve of internet fame. For the rectifier tube I used the Sovtek 5AR4 which provides from 440-465 volts DC depending on bias and output tubes. This is a rock solid rectifier tube. The output tubes I chose are reissue Tung Sol 5881's. They have great bloom and ooze vintage tone. With these tubes installed the amp is set to run at 25 ma per tube at 450 volts - lots of clean headroom, but a really nice vintage SRV grind with the volume past 5. I have mounted the 1.5k series grid resistor with zero lead length before the socket pin to avoid any parasitic oscillations. The preamp tubes are a mismatch that I selected for noise, microphonics, and tone in this circuit. The Normal channel preamp tube is a Sovtek 12AX7LPS - a great combination of low noise and great tone in the Fender circuit. The Vibrato Channel has an NOS Ruby 12AX7. This channel took a lot of tweaking and trial and error to find the right tube. This channel has a lot of bass and gain - so the Ruby was a great fit for both single coil and humbucker equipped guitars. The Reverb driver tube is a NOS JAN Phillips ECG 12AT7. What can I say - no compromises - great tone. The Reverb recovery tube is a Groove Tubes 7025 (12AX7) silver plate. It looks to be a YUGOSLAVIAN Ei. This tube is a little brighter and has no microphonics - the perfect choice after the reverb circuit. The vibrato tube is an Ei ECC83 - this is not an audio tube - so any one will do - but I went with the Ei. The Phase inverter is another NOS JAN Phillips ECG 12AT7 - the perfect amount of gain and stability - it can also take the higher voltages in this stage of the amp.

You will notice I have original style reverb cables for this amp to keep the original look and feel. Using original braided shield cable and NOS RCA connectors I made the cable myself. The power cable is very similar to the original grey power cable, only I used a grounded plug for safety. Another detail I have built into this amp is all the ground connections to the chassis and ground buss are soldered. I had to buy a special 300 watt soldering iron to do this, but it was a must to keep the original layout and look of this amp. The speaker cable is 18 gauge solid conductor vintege push-back wire using the original style round distribution board screwed to the baffle board to run all four speakers in parallel. The speaker plug is an original right angle plug with the authentic Fender "F" plug cover. The reverb tank is a new Accutronics 4AB3C1B 2- spring reverb tank. The tolex bag is an original fender bag from my 1968 Bandmaster Reverb.

As you can tell - I have tried to spare no detail on this amp. It was a labor of love. Inevitably I have forgotten some small detail that is important to you - so since I custom-built this amp Please email me with any and all questions you have. I promise to answer your questions quickly. This amp comes with an original FENDER amp cover.