CGS Wave Multiplier
Quantity: 1
From Ken Stone’s CGS website:
The idea for this project came from the fabled middle section of the Serge wave multipliers. … The circuit I came up with I would describe as a “reflector”, and is ingeniously simple. Going on it’s performance, I would guess it to be very close to Serge’s original design.
In addition to this multiplier, there is a second simple multiplier created by adding lag to the feedback path of an op-amp. The results are remeniscent of a well known tube modulator.
For the primary multiplier, the “folder”, connect the input to the triangle wave output of a VCO. Connect a LFO, envelope generator or even a DC voltage to the folds input. The result will be a harmonically rich signal at the “FOLD” output. A second input based on a lag circuit allows square waves and other hard-edged waveforms to be used as the signal source.
There is also a “PULSE” output available, with “pwm” inputs to further vary the posibilities.
To use the second multiplier, the “grinder”, feed the input from the output of a VCO. Adjusting the “drive” and “lag” pots will give variation to the output signal.
Obviously both multipliers can also be used to mangle control voltages, the outputs from LFOs etc.
Modifications:
Stooge Panel
Some parts changes:
- At IC4a change 47K to 100K to double the PWM CV sensitivity.
- At IC4b pin 7 use a 3K3/1K8 divider to change the PULSE OUT level to +/-5V.
- At IC2b pin 6 change 100K to 33K for FOLD CV input to increase sensitivity.
- At IC1a add a 100pf capacitor between pins 1 and 2 to eliminate parasitic oscillation in the GRINDER.
- Add a 1K resistor to ground at GRINDER OUT to cut the amplitude in half, as it can clip at the power rails.
Hello richard, I would be interested to know how this compares to the oakley Discontinuity module,or what you understand about that module? Wave folders and the like intrigue me but Im never quite sure what the theory is behind these circuits or what they are doing and there are many variations. Is there a way to kluge something using basic modules to get an idea?
I don’t have the Oakley Discontinuity and really can’t compare it with the CGS wave multiplier. Suggest looking at the CGS site for Ken Stone’s description and explanation of how it works. In any case the sound of Ken’s circuit is distinctive and can produce a wide variety of timbre changes, depending on the waveforms going in. I use it more often than some of my filters.