Boss GE-7 Equalizer pedal schematic diagram

The Boss GE-7 Equalizer pedal adjusts the harmonic contents of an instrument in 7 separate bands ranging from 100Hz to 6.4kHz, with a boost/cut 15dB per band. The additional Level control knob helps you to set a different volume for normal and effect sound (or to use the pedal only as a gain booster).

Schematic diagram of GE-7 equalizer pedal
Fig. 1: Boss GE-7 Equalizer guitar pedal schematic diagram
 
GE-7 equalizer circuit board
Fig. 2: GE-7 circuit board - foil and component side
Boss GE-7 equalizer pedal
  • Residual Noise Level: -100dBm (IHF-A Weighted, Typ.)
  • Equalizer Control: +/- 15dB
  • 7 band EQ: 100Hz, 200Hz, 400Hz, 800Hz, 1.6kHz, 3.2kHz, 6.4kHz
  • Level Control: +/- 15 dB
  • Connectors: INPUT Jack, OUTPUT Jack, AC Adaptor Jack (DC 9V)
  • Power Supply: DC 9V Dry Battery (6F22/9V), AC Adaptor
  • Current Draw: 7mA (DC 9V)
  • AC Adaptor: ACA-Series or PSA-Series (new models with silver label)
  • Width: 70 mm
  • Depth: 125 mm
  • Height: 55 mm
  • Weight: 450g

ICs, transistors and diodes used in the Boss GE-7 equalizer:

  • IC1, IC2,IC3: TL022CP dual operational amplifiers
  • IC4: uPC4558C dual operational amplifier
  • IC5: HA1457W preamplifier
  • Q1: 2SC732TM-GR NPN silicon transistor
  • Q2, Q3: 2SC945-P NPN silicon transistor
  • Q4, Q5: 2SK30ATM-Y N-channel JFET transistor
  • D1, D2, D3: 1S2473 diodes
  • D4: RD5.6EB3 500mW 5.6V Zener diode
  • D5: 1OE2 diode