The Vocoder 71A is a solid DSP interpretation of the classic Vocoder effect. Analogue Vocoders that offer an adequate number of filter bands can be a challenge to manufacture with high parts count, large circuit boards and enclosures and lengthy calibration procedures. All of which adds up to high costs and large dimensions. The 71A attempts to address this, providing the most important features of a mid range Vocoder in a small package ideal for a modular environment.

To keep the footprint small we chose a simple "tone" knob which provides a "tilt" like control that scales the high and low bands with center position being flat. This method combines considerable space saving and versatility without the need for individual sliders for band levels. It also makes it possible to have with voltage control.

The filter/envelope detector network uses ten 4 pole 24dB band pass filters which we found to provide good frequency isolation, important for clarity when used with vocals or speech. Also works very well processing Drum loops and other sources.

  • Features:
  • 10 bands with 4 pole 24dB response.
  • Squelch feature functions as a noise gate
  • Individual Attack and Release Envelopes with voltage control
  • Tone control in place of band level sliders with voltage control
  • Three output modes with invert and odd/even split
  • for interesting pseudo stereo effects.
  • Individual level attenuators for Mod and Carrier inputs
  • Clipping LEDs for level
  • Built in compression for Modulation input for improved low dynamic signals like voice.
  • Firmware by Eric Brombaugh

Sample Rate: 45kHz
Sample Resolution: 16-bit
Output: typical 2V RMS@1Kohms
Input: typical 5V pk-pk@100Kohms
Input CV: 0 - +5V @100Kohms
Power: +15V @110mA, -15V @20mA