This module incorporates two buchlaidian
types of voltage and audio processing.
The CD processor is designed to give Buchlidian
type processing for control voltages. Two channels,
both with manual +/-processing, offset & glide
controls. This circuit was originally based on a
Chris MacDonald design modified by Peter Grenader.
Besides some minor changes i incorporated a lag pot,
a trimmer for calibration of a center taped pot
(+/-processing) and there's a resistor missing in
the original schematic to bring the LEDs to live.
BTW wiring the offset pot between the supply rails gives
you the possibility of negative offset, too...
The dual low pass gate is Peter Grenaders
adaptation of the classic 292C from
the Electric Music Box. He substituted
a DPDT ON-OFF-ON switch for the 4016
analog switch originally used.
Dual CV Processor
birth of the low pass gates
LPG Low Pass Gate
containing schematics, and both the old layout and a new one, providing the additional resonance mod.
Boards before 16 JUL 09:
if you already have etched a board with resonance from the documentation before 16 JUL 09 you will have to add this little mod: just add a little jumper on the boards reverse side (missing trace shown in red).