ST Modular Honeyeater

This is a CEM3340 based VCO that packs a bunch of punches in a small package. I picked up the PCB and panel from Pusherman’s Store. More info on this circuit can be found at ST Modular’s website.

Details:
• Analog VCO
• Fabled CEM3340 Sound
• Mixable Waveforms
• Noise Source
• Two Sub-Octaves
• Linear or Exponential FM
• Pulse Width Modulation
• Hard or Soft Sync

I just can’t believe how great this thing sounds.

Calibration notes from ST Modular FB Group

Use a midi to CV converter and a tuner, set the Tune and/or Fine pot to reach C, play C1 and C2 alternately and check if it stays on C. Adjust the v/Oct trim pot on the front if it’s off a bit. Repeat that for C2 and C3 and so on. Adjust high freq trim if you can’t get higher octaves right. Adjust v/octoffset to reach the correct note. You may also use an oscilloscope or a multimeter in audio frequency mode and using a quantizer in octave mode to adjust frequencies of 100hz, 200hz etc. Keep in mind to calibrate only after heating the osc up for about 20 mins.