Boss DD-2 Digital Delay pedal schematic diagram

The DD-2 is one of the best digital delay pedals and actually sounds very analog! The pedal was sold from 1983 and it did officially go out of sale 1986 but it was relaunched without changes as the DD-3 (later versions of the DD-3 use a different design). The circuit is built around the RDD63H101 IC and a 12 bit A/D converter producing a flat frequency response between 40Hz and 7kHz. It generates a delay time of 12.5 to 800 milliseconds and offers a useful sample/hold feature.

Boss DD-2 Digital Delay Pedal Schematic Diagram Fig. 1: Boss DD-2 Digital Delay guitar pedal schematic diagram
Boss DD-2 Digital Delay guitar pedal
  • Controls: Effect Level, Feedback, Delay Time, 4-way Mode switch
  • Connectors: Input, Output, Direct Out, AC Adaptor
  • Input Impedance: 1MΩ
  • Recommended Load Impedance: > 10kΩ
  • Residual Noise Level: -95dBm (IHF-A, Typ.)
  • Delay Time: 12.5ms to 800ms
  • Hold Time: 200ms to 800ms in Hold mode
  • Frequency Response: 40Hz to 7kHz (delay) and 10Hz to 60kHz (direct sound)
  • System: Analog logarithmic compression and 12 bits quantizing system
  • Recommended AC Adaptor: PSA Series
  • Current Draw: 45 to 65 mA (DC 9V)
  • Dimensions: 70(W) x 55(H) x 125(D)mm
  • Weight: 450g