Basic Distortion Circuit PUBLIC

Basic Distortion Circuit for Guitar with 2-Band Tone

Basic distortion circuit for guitar with 2-band James-style tone-controls. Uses one dual JFET-input op-amp to provide gain and active tone. Controls Include: Distortion, Drive, Bass, Treble, and Volume. Range above 0 dBV is from 30 Hz to 15 kHz. Suitable for 6/7/8-string guitar or 4/5/6-string bass, though emphasizing mids between 250 Hz and 2.5 kHz with all controls at 50%. Maximum gain = +17.8 dBV (Vo/Vi = 7.8) @ 400 Hz with all controls at 50%, or +43.2 dBV (Vo/Vi = 145) @ 160 Hz with all controls at 100% [also +40.2 dBV (Vo/Vi = 102) @ 2.5 kHz, and +39.8 dBV (Vo/Vi = 98) @ 1 kHz]. The effect of the Treble controls is to cut amplitude at 10 kHz to -2 dBV and at 16 kHz to -8 dBV, or boost 10 kHz to +9.5 dBV and 16 kHz to +5.2 dBV. The effect of the Bass control is to cut amplitude at 100 Hz down to +5.5 dBV and at 40 Hz to -6.7 dBV, or boost 100 Hz to +20.8 dBV and 40 Hz to +15 dBV. Midrange is fixed and corresponds to the said emphasized frequency band. Power-supply not shown. Requires a regulated dual-polarity DC supply providing +-9VDC or +-12VDC or +-15VDC at >= 20 mA of current.