Tubulation II Distortion PUBLIC

Tubulation II MOSFET + Op-Amp Distortion Circuit

Largely the same as the Tubulation I Distortion circuit, but with a different 3-band tone-control circuit, and some re-adjusted part-values. Controls Include: Input Gain, Clean Level, Clean Bass, Clean Mid, Clean Treble, Distortion 1 Gain, Distortion 2 Drive, Distortion 2 Gain, Distortion Tone, Distortion Attenuation, and Output Gain. As with Tubulation I, Distortion 1 is obtained from overdriven depletion-mode MOSFETs while Distortion 2 is from an overdriven op-amp. But the MOSFET IC can be replaced by a 12AX7A preamp tube; with directions given at the bottom of the diagram. Frequency Range 20 Hz to 36 kHz with all controls at 50%. Suitabloe for 6/7/8-string guitar or 4/5/6-string bass. Maximum Gain = +24.4 dBV @ 1.6 kHz with all controls at 50%, or > twice that with all controls at 100%. As a rackmount project, the battery should be replaced by a regulated +12V DC power-supply. Also, treat the circuit as experimental. Breadboard test before soldering. For more details, see Description for Tubulation I.