This is a multi-purpose module that can be used in a number of ways. It can be used for basic logic functions to generate complex gates. Using multiple inputs allows the creation of a variety of different but related gates which can be used to create complex but nicely sync’d patches. There is a R2R ladder to create a stepped CV signal that corresponds to the gate outputs, this is also fed thru a gate (or CV) controlled sample & hold/Slew circuit to create a smooth output.
Some tricks (depends on your choice of logic):
- Use the module to process audio signals and feed the outputs back into other inputs.
- The BOOLs can be used as an envelope generator. Choose an input to determine the height (1 = low, 4 = high), set the slope with the Slew pot, feed the S&H input with various signals to vary the envelope shape.
Suitable chips are
- 4001 NOR
- 4011 NAND
- 4071 OR
- 4081 AND
- 4077 XNOR
- 4030 or
- 4070 XOR
For me, the OR, XNOR & XOR chips are the most interesting. What makes this circuit a little different is the way the inputs and outputs are related. There are four inputs, call them A, B, C & D, say we have an XOR chip installed and signals on all four inputs Output 1 will be A xor B Output 2 will be B xor C Output 3 will be C xor D Output 4 will be D xor A
The input signals can be pretty much anything that crosses 1.1V. Outputs will be 5V. Audio rate signals are fine; XOR chips give a crude but useful ring modulation effect.
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