Bassman AB165 to AA864 mod

This kit includes all of the electrical components, diagrams & written directions you need to perform a full blackface conversion on your silverface Bassman 50 amplifier, converting it to the coveted AA864 blackface Bassman phase inverter, bias supply and output coupling circuitry!

If you have an “AB165″ Bassman, then our “AB165 to AA864 conversion” kit is for you.  This kit is for silverface AB165 amps with the brick red signal caps (and sometimes thin black caps on the left side of the circuit board, and maybe a few .047 bluemolded caps in the preamp).  This kit is NOT for early silverface amps LOADED with BLUE MOLDED CAPS!

PLEASE NOTE: The end result of the Bassman 50 blackface kit and AB165 to AA864 mod kits are the same.  The two amps have different starting points hence different instructions.  While this kit can theoretically 'work' on either model, getting the correct kit with the correct instructions will make the experience much smoother and easier.

PLEASE NOTE!!  If you have a BLACKFACE AB165 Bassman WITH BLUE MOLDED SIGNAL CAPS, we have a special kit for that amp, specifically designed for BLACKFACE AB165 Bassman amps with the Blue ‘Molded’ signal caps!  (Also for 'Drip Edge' silverface and early silverface versions with the Blue Molded signal caps).  

It converts the phase inverter to classic AA864 specs (the same circuit as found in the classic blackface AB763 amps, such as the Twin Reverb, Super Reverb, Deluxe Reverb etc). It also converts the Bass channel to a tweed style preamp!!!
The major bonus here is that you get to keep all of the highly regarded Blue ‘Molded’ signal caps in the amp!  In doing both the AA864 conversion and tweed preamp mod, you swap two signal caps from the phase inverter with two caps from the Bass channel and re-purpose these fantastic caps!!  NONE are removed from the amp!
NOTE: This will also work in the early silverface AB165 amps with Blue ‘Molded’ caps!  This kit is ONLY FOR AMPS WITH BLUE MOLDED SIGNAL CAPS!!!
Get your AB165 to AA864 for BLACKFACE amps with BLUE MOLDED caps PLUS TWEED MOD here

(Tools, solder & wire NOT included).

*Complete, detailed, easy to follow instructions with “before & after” diagrams are included.

*Complete instructions for removing the master volume & push/pull gain boost are included (where applicable).

*Only the highest quality Nichicon electrolytic capacitors are included in this kit.

*Only the highest quality carbon resistors are used in the signal path.  Flameproof metal oxide resistors are used for the high voltage applications in the power supply & bias supply.

*Instructions for reading color codes on resistors included.

WE NOW OFFER NOS SIGNAL CAP UPGRADES IN 'PREMIUM' BLACKFACE MOD KITS!
We now proudly offer NOS rolled foil/mylar signal cap upgrades for our premium blackface mod kits!  These selected NOS capacitors replace the standard ceramic caps used in our standard kits (as found in the original blackface amps).  The entire preamp signal passes through this one cap on the way to the phase inverter, and the quality of this one cap has a significant impact on the tone and performance of the entire amp. These NOS mylar caps bump everything up a few notches, giving you more depth and dimension (more of a '3D' sound), a bit more clean sustain, and more 'oomph' overall; with smoother, sweeter top end. Don't get me wrong, the ceramic version is excellent and true to the original blackface models!  But the NOS version is definitely a significant upgrade, giving you 'more of everything' we like about vintage Fenders!
We also offer M150 and 6PS Orange Drop signal cap upgrades in our plus kits.

BONUS: Certain resistors, vital to optimum performance of your amplifier have been measured & matched by tolerance percentage!!   You are getting a matched set for your output section!  This ensures maximum efficiency, optimum performance and the best possible tone from your Fender!  Not only are you blackfacing the circuit, you are optimizing the output stage!

As a bonus, the necessary resistors & detailed instructions on how to properly set the bias of your newly blackfaced amp (using only a multimeter & calculator) are included.

Please note:  These kits are designed for the “standard” Fender silverface amplifiers.  If your amp is “ultralinear”, these kits are not intended for your amp.  You can tell if your amp is ultralinear by looking under the speaker jack on the back panel.  ALL 70 watt & 135 watt models are ultralinear!!  

For 70w UL amps, please check out out '1/2 blackface mod'