A couple of years ago, I was lucky enough to acquire a 1950 V-Front Super in a trade. The V-Front cabs used on the Dual Professionals and early Supers were a thing of beauty. This one was a mess, but had good bones, as the saying goes. Since the tweed had been replaced with some hideous yellow vinyl many moons ago, I decided to send it to Will Dyke for a re-tweed and a heavy relic, since the rest of the amp was well worn. While it was there for the rehab, I asked Will to take measurements and reverse-engineer it for a future project I had in mind. That project evolved into the Fullerton™ 5F6-A which in my opinion, combines Leo’s most iconic amp circuit with his most elegant cab design.
Starting with the 1960 Tweed Bassman circuit, an additional preamp tube was added to allow for both a 12AY7 and a 12AX7 to be dedicated to the “Normal” channel. The 12AY7 is the stock tube in the V1 position, but the 12AX7 can be switched in on the fly. The Normal channel retains all the character of a stock Bassman’s Bright channel. The “Bright” channel was then re-voiced as a JMP50 lead spec for a more British sounding vibe. The channels can then be internally jumpered, yielding a variety of classic rock tones. A switchable tube/SS rectifier, adjustable negative feedback, and Rich II Mod PPIMV were also added to increase the tonal possibilities, without altering the 5F6-A’s basic DNA. The chassis was then installed in a custom relic’d 2×10 V-Front cab from Will Dyke at Armadillo Amp Works. The result is the Fullerton™ 5F6-A.
While the 5F6-A’s schematic and layout are readily available in the public domain, Fender built the 1960 Bassman with several deviations from that published spec as it entered it’s final months of production. Many feel that original amps from this period have exceptionally good tone, or an “it” factor, as a result of these factory tweaks. Subjective? Yes. However, all we know is that this version of the 5F6-A rocks!
Fullerton™ 5F6-A Features:
- “Normal” channel is a stock 5F6-A Bright channel voicing that can be switched between a 12AY7 or a 12Ax7 with the volume’s push/pull pot
- “Bright” channel is re-voiced with a JMP50 lead spec preamp with channel jumper feature on the volume’s push/pull pot
- Rich Mod II PPIMV (Post Phase Inverter Master Volume)
- Switchable tube/solid state rectifier; tube for “sag” and SS for “tight”
- Switchable negative feedback; choose between stock 5F6-A, JTM45, or 5E3
- Metropoulos “Zero-Loss” FX loop upgrade available (+ $175)
- Adjustable bias pot on underside/inside of chassis
- 4/8/16 ohm selector switch
Fullerton™ 5F6-A Components & Specifications*:
- Custom V-Front 2×10 combo cab beautifully relic’d by Will Dyke at Armadillo Amp Works
- (2) Eminence 1028K 35W Alnico speakers
- Mercury Magnetics FO50BM-16 output transformer based on the legendary Triad 45249 used on the 5F6-A Bassman and the early 5g12 Brown Concerts
- Heyboer custom wound power transformer; vintage spec and voltage adjusted based on the Triad 8087
- Hammond 194G 3H 250mA choke
- Old-school hand wired construction with our custom-made G10FR ‘glass eyelet boards
- Jupiter “Red Astron” vintage-style capacitors
- Sprague, F&T electrolytic capacitors
- Carbon composition, and metal oxide resistors used in key locations for vintage tone and maximum reliability
- Belton sockets, Carling switches, Cliff jacks
- CTS, Bourns and PEC potentiometers
- 40 watts, (2) Sovtek matched 5881’s; (1) JJGZ34; (1) TAD 12Ay7, (3) JJ 12AX7’s
- Heavy Duty 14AWG 10′ power cord
- 46 lbs.
*Components and Specifications are subject to change without notice due to availability, or to improve reliability, function, design or otherwise.