Boss OD-1 OverDrive pedal schematic diagram

Boss OD-1 OverDrive was one of BOSS' first compact effects pedals, and offered a number of new features including silent FET switching to eliminate pops and clicks, rubber panels on top and bottom, quick-access battery compartment and recessed knobs. The OD-1 was first sold in 1977 and was discontinued in 1985. The pedal was very popular, thanks to its smooth responsive overdrive tones that guitarists couldn't resist. The OD-2 and SD-1 took over from the OD-1 later, but many guitar players still use this effect because of its pure sound. The OD-1 (like the OD-2 and SD-1) uses asymmetrical clipping, for a smoother, warmer, less edgy distorsion effect.

Boss OD-1 OverDrive pedal schematic diagram Fig. 1: Boss OD-1 OverDrive guitar pedal schematic diagram
Boss OD-1 component side (ET-23D version)
Fig. 2: Boss OD-1 OverDrive circuit board - component side (ET-23D version)
Boss OD-1 OverDrive guitar pedal
  • 2 Controls: Level and Overdrive
  • Connectors: Input, Output, AC Adaptor
  • Input Impedance: 470kohm
  • Output Impedance: over 10kohm
  • Signal/Noise Ratio: over 80dB
  • Recommended AC Adaptor: ACA Series
  • Current Draw: 3.5mA DC 9V
  • Dimensions: 70(W) x 55(H) x 125(D)mm
  • Weight: 400g

The original OD-1 OverDrive was made with the RC3403ADB op-amp IC. Some early pedals from 1978 used a NEC uPC4741C quad operational amplifier.

Later models used different versions of the 4558 8-pin dual op-amp: NJM4558D, uPC4558C, uPC4558C, TL4558P, JRC4558D, JRC4558DD, JRC4558DC and C4558C.

ICs, transistors and diodes used in the OD-1 OverDrive:

  • IC: RC3403ADB, uPC4741C, NJM4558D, uPC4558C, uPC4558C, TL4558P, JRC4558D, JRC4558DD, JRC4558DC or C4558C (depending on your model)
  • Q1: 2SK30ATM-Y (N-channel JFET transistor)
  • Q2: 2SK30ATM-GR (N-channel JFET transistor)
  • Q3, Q4, Q5: 2SC945-P 2SC1815-Y (NPN silicon transistors)
  • Q6, Q7: 2SC732TM-GR (NPN silicon transistors)
  • D1: RD11EB-3 (500mW 11V Zener diode)
  • D2: RD5.1EB-3 (500mW 5.1V Zener diode)
  • D3-D10: 1S2473 or 1S1588 (switching diodes)
  • D11: SLP135B (LED)