Modified TS-9 Tube Screamer PUBLIC

Modified Ibanez TS-9 "Tube Screamer" Overdrive Circuit

Highly-modified Ibanez TS-9 "Tube Screamer" overdrive circuit. Controls Include: Drive, Tone, Treble Boost switch, Level, and Master. Frequency range between low and high 0 dBV points is from 40 Hz to > 25 kHz with all controls at 50%, and given a 1V 1kHz input signal. Suitable for 6-string guitar (not for 7/8-string guitar or bass-guitar). Maximum gain = +24.9 dBV (Vo/Vi = 17.6) with all controls at 50%, or +31.8 dBV (Vo/Vi = 38.9) with all controls at 100%, at which bandwidth extends from 10 Hz to 28 kHz. Thus, this circuit provides only modest gain. Modifications: Addition of op-amp input buffer, upgraded BJTs, changes in some part-values (to help reshape response curve), and addition of output op-amp to get more overall gain. Can be used as a stomp-box or rackmount project, and the battery can be replaced by a regulated single-polarity +9VDC power-supply providing >= 60 mA of current. And though simulator verified, treat the circuit as experimental. Breadboard test it before committing to a soldered build.