Boss OD-2 Turbo OverDrive pedal schematic diagram

The OD-2 was manufactured as a replacement for the OD-1 in the mid 1980s and uses only discrete components. It has 3 potentiometers for level, drive, tone control and a switch for selecting two modes of operation. When set to the OFF position the sound is similar to the OD-1 but in the turbo mode it generates more gain and distortion.

Boss OD-2 Turbo OverDrive pedal schematic diagram Fig. 1: Boss OD-2 Turbo OverDrive guitar pedal schematic diagram
Boss OD-2 Turbo OverDrive PCB component side and foil side
Fig. 2: Boss OD-2 Turbo OverDrive circuit board - component side and foil side
Boss OD-2 Turbo OverDrive guitar pedal
  • Controls: Level, Tone, Drive, 2-way Mode switch
  • Connectors: Input, Output, AC Adaptor
  • Input Impedance: 1Mohm
  • Output Load Impedance: 10kohm or more
  • Equivalent Input Noise: -118dBm or less (IHF-A, Tone center, Input Short)
  • Recommended AC Adaptor: ACA Series
  • Current Draw: 10mA @ 9V
  • Dimensions: 70(W) x 55(H) x 125(D)mm
  • Weight: 410g (14 oz)

Transistors and diodes used in the OD-2 Turbo OverDrive:

  • Q1, Q6, Q8, Q9, Q21: 2SC945-P (NPN silicon transistors)
  • Q3, Q4, Q7, Q16, Q17: 2SK30A-Y (N-channel JFET transistors)
  • Q5,10,11,13,14,18,19: 2SK117-GR (N-channel JFET transistors)
  • Q12, Q15, Q20: 2SA970-GR (PNP silicon transistors)
  • Q2: 2SC2240-GR (NPN silicon transistor)
  • D1,3,4,5,7,9,10,11,12: 1SS-133 (switching diodes)
  • D2: S5500G (400V/1A rectifier diode)
  • D6: RD6.2JB-2 (6.2V Zener diode)
  • D8: MTZ6.6 (6.6V Zener diode)
  • LED: LN28RP (red LED)