Quaalude - model T style preamp/distortion
Quaalude is my recreation of the fabled Sunn Model T amplifier sound in a preamp pedal format. It's circuit topology is based on original amp's schematic and executed with matched JFET transistors. Each circuit stage is carefully tuned to provide different operation conditions, just like in a real amp, and vast amount of available tones. Transistor will probably never replace real tubes for their sound, but I believe Quaalude gets as close as it's possible with 9V power supply operation. Pedal includes 3-band FMV tone stack (voiced just like the original first gen Model T) and additional dirty boost section in front of the preamp, which can be used independently or stacked together.
Quaalude can be used not only as a standalone overdrive/distortion pedal, clean preamp, booster or other pedals 'platform', but it's huge output volume also allows to stack it straight into external power amplifier - thanks to the high gain output stage providing additional volume capacity and tone shaping, for even more real Model T resemblance.
Please see block diagram document representing internal stages sequence to better understand pedal operation. Each stage of pedal's circuit provides different harmonic content, so distorting any of them yields in a different overall sound.
- boost sets dirty booster output level
- normal/brite knobs set channels output level
- bass/midrange/treble - interactive EQ
- volume sets total preamp output level, the same operation as 'master volume' knob in Model T amplifier
- master - true master volume control (at the very end of Quaalude's circuitry).
BE CAREFUL with tweaking volume and master knobs - pedal can get deafening loud. Best setting to start is master maxed, volume, normal and brite at 9 o'clock. Turn channels to taste and eventually alter master to volume relation.
- boost gain switch - left position for moderately dirty boost, right position for very dirty boost
NO BATTERY OPERATION POSSIBLE WITH THIS PEDAL. Feed it only with standard 9V DC negative center power supply.