Pico controlled AD9833 dual DCO with AS3340 waveshaping
Searching for a stable DCO with sawtooth, PWM, triangle and SUB waveforms. I was watching a video on the CEM3340 and it's waveshaping capabilities. It seems that it is a triangle core with waveshaping for it's ouputs.
The AD9833 is capable of triangle, square and sine wave outputs, all of which are difficult to convert to a sawtooth. I experimented with injecting the triangle (amplified) of the AD9833 into the AS3340 triangle input buffer and eventually found a signal that triggered the wave conversion.
Based on this and an RP2040 controlling the AD8933 frequencies it was possible to construct a MIDI controlled dual DCO with upto 8 waveform outputs. 2 saw, 2 PWM, 2 triangle and 2 sub outputs.
- MIDI controlled
- Dual oscillators
- Osc2 Detune (MIDI controlled)
- Osc2 Interval 0-12 semitones (MIDI controlled)
- FM input 0-3.3v (center 0 modulation)
- Sawtooth 0-10v x2
- PWM 0-10V x2
- Triangle 0-10v x2
- Sub oscillator 0-10v x2
- Velocity output 0-5V
- Keytrack CV output 0-5V
- Keytrack scaling and on/off
- Oscillator Sync based on P600 softsync
- Pitchbend +/- 1 octave (MIDI controlled)
- Octave select -/0/+ 1 octave per DCO (MIDI controlled)
- Glide (MIDI controlled)
- PWM CV input 0-10V x2
- Gate output
- Trig output (10mS)
- CC 5 - glide time 0-127 (0-4000mS)
- CC 65 - glide off/on >63 = on
- CC 17 - DCO1 octave select (0-127) -1 / 0 / +1
- CC 18 - DCO2 detune (0-127)
- CC 19 - DCO2 octave select (0-127) -1 / 0 / +1
- CC 20 - DCO2 interval (0-12) 0 - 12 semitones
- CC 21 - Keytrack scale (0-127) 0-100%
- CC 22 - Keytrack off/on >63 = on
- CC 23 - Sync off/on >63 = on