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Big and powerful, yet refined, the Formula No. 55 melts into your amp, transforming it into a wide ranging tweed monster!

The Formula No. 55 is a Foundation Overdrive that reproduces, in exact detail, the preamp section of the classic Fender™ tweed 5E3 Deluxe using an all-discrete JFET-based signal path. The Volume and Tone controls replicate, part for part, the circuitry of the 5E3, giving you authentic tweed amp response. The output section is designed to give you punch and volume with a low output impedance to drive your amp perfectly. Set the Hi-Lo button to "Lo" for the cleaner response of a vintage tweed. "Hi" is like hot rodding your amp by swapping in higher gain tubes.


PRESENCE: This control governs frequencies in the 5khz range allowing you to tune the top end response to your particular pickups and amplifier. 

MASTER:This volume control has a heaping helping of output on tap, allowing you to dial in a huge, fat, woody clean tone or to push your amplifier into overdrive all on it’s own.

TONE:This parameter sounds and behaves just like it does on the actual Deluxe amplifiers - you will notice that as you wind up the VOLUME control that the TONE control’s influence becomes more subtle when the VOLUME is maxed out. At lower VOLUME settings, you can set it at noon for the flattest response; to the left of noon for those smoky jazz cleans; or crank it up for more barking, greasy upper midrange tones that slice through the mix. 

VOLUME: The VOLUME control is essentially your gain control. It works in concert with the HI/LO switch, enabling you to set your maximum desired level of dirt - from squeaky clean to DAMN THAT’S STANKY! Want to clean it up? Simply roll back your guitar’s volume knob! 

The HI / LO switch offers two discrete gain modes:

The HI / RED mode is the raging, hot-rodded 12AX7 mode with more gain and saturation. You’ll notice that your pick essentially turns into a ‘throttle’ of sorts - lay off the attack and it cleans up but there’s always that potential there for ‘acceleration’ when you lay into it!

The LO / GREEN mode is lower gain overall - as if your amp were now sporting 12AY7 preamp tubes. Cleaner and more immediate in the pick attack with more ‘bounce’ when you’re chord comping, but still has that fat, juicy harmonic response.

You can power your Formula No.55 with a 9v battery or any good quality filtered andregulated 9-18vDC power supply with a center-negative tipped plug designed for use witheffects pedals. If you want more volume, headroom, and percussive attack, try running an18vDC power supply. A 9vDC power supply will have a slightly softer sound that saturates more easily - it's sort of like the difference between a 50 watt and 100 watt amp! Definitely try it at 18 volts though - there's quite a difference! 18 volts is great for playing with the band.You'll get great attack and clarity with power to cut through the mix. You can also try a battery that is drained down to as little as 3-4 volts to get an even softer sound that is great for late night jam sessions when you don't want to wake anyone up!To change the battery, just remove the four screws on the bottom plate. There are no other user controls under the hood. As usual, when running with a battery, unplugging the input jack will turn off the power.