The FX10 Bi-FET Preamp was derived from DOD's 210 FET Preamp and 410 Studio Bifet Preamp.
Notable IC chip: one TLO62CP dual op-amp, with half used for the Level control (and functioning as a buffer) and the other half used for the Tone control; each control used its own J113 (or equivalent) field-effect transistor (FET)
Designed as a preamp for acoustic instruments (such as piezo-equipped acoustic-electric guitars), the FX10 can also serve as a "clean boost" pedal for electric guitar. Its Tone control allows either bass or treble boost, with the center position providing a flat response. The FX10 was one of the original ten DOD FX-series pedals that debuted in 1982, and remained in production through at least 1995.