2001 Fender Tonemaster

These amps were designed by famed boutique tube-amp guru Bruce Zinky in the 1990’s… so not the “Tonemaster” amps currently made by Fender that are cheap digital modeling toys made like a cell phone. The Zinky Tonemaster is an 80 watt all tube hand-wired affair that was produced by the Fender Custom Shop along with a handful of other designs also by Bruce in different wattages and topologies. The Tonemaster became very popular with Joe Perry of Aerosmith and Dave Grohl of The Foofighters. Circuit design is based heavily on Tweed and Brown-Panel Fender amps of the late 1950’s/early 1960’s. They have a clean channel and a cascading gain stage overdrive channel, as well as the very odd choice of transformer driven effects loops. These amps are made very well overall but have some issues: The first being that they are made with middling quality Illinois Capacitor brand TTAA series electrolytics (grey outer sleeve) that do not last more than 2 decades at most (I have seen failures as early as 7 years) ; The second inexplicably being that the power tube grid stop resistors are placed very far physically from the octal sockets where they should be mounted - this commonly causes out of control oscillation at any real volume level. I have never seen this last problem in any mass produced amplifier, ever. This amp needed these things addressed as well as a new set of tubes.

Amp was completely restored. All filter/bias/bypass caps were replaced with upgraded voltage and temperature rated F+T/MOD/Vishay/IC brand electrolytic’s. As I said before Illinois Capacitor Co. is not my favorite manufacturer but sometimes they are the only one that makes replacement parts for amps they were originally used in - in that case I use the much better quality TTAM series (blue outer sleeve) that seem to hold up better. New 2 Watt Metal Oxide/1 Watt Carbon Film power dropping resistors were installed for better reliability and lower noise floor. All screen resistors were replaced with 3 Watt Cement 470 ohm type units for same reasoning. All power tube grid stoppers were replaced with 1/2 Watt Carbon film type units and physically moved to the correct location which is not on the eyelet board but directly soldered to pin 5 of the octal sockets - this accomplished getting rid of the oscillation and noise that plagued this amp from the factory.

The original tubes did not test good and were all replaced: V1-V3 = JJ 12AX7S, V4-V7 = Tungsol 5881 Matched Quad. These tubes were picked for best tone, reliability, and to lower the chance of parasitic oscillation. The Tonemaster amps are extremely picky with power tubes - they only like Sovtek or Tungsol 5881’s. All 6L6GC’s cause major issues with this amp as well as 5881’s made by other brands like JJ. The grid stopper problem and messy wiring are the cause of this, however only one of these faults can be solved so we still have to obey this rule of thumb. The 5881's Fixed Bias was set to %52 Class AB Plate Dissipation with a B+ of 464VDC. The pots were sprayed out with De-Oxit and the amp was cleaned inside and out. This amp sounds fantastic and is a cool pice of Fender history.