Chopper

An analogue switch on steroids, after a 1975 paper on a nonlinear delta modulator (S.K. Mullick and K.R. Srivathsan): the two signals being switched also decide when the switch flips, through a slewed comparator, with CV and the COMP knob on top. It works as a VCO, a VCF, a waveshaper, a ring modulator, an LFO or a VC gate generator. The comparator gives two complementary gates; CHOP OUT is the switch's output, SLEWY its slewed one. Below it a separate bi-directional switch, functionally the early Serge bi-di router on a DG411: GATE sends A/B to A or to B, or A and B to A/B. COMP IN is wired to CHOP IN1's switch, so a CV alone sets it running.

Key features

• COMP IN, CHOP IN1 and CHOP IN2 in; COMP OUT1 and COMP OUT2 gates, CHOP OUT and CHOP SLEWY
• COMP and SLEW knobs; a bi-directional switch: GATE, A, B and A/B
• Four LEDs
• 8 HP; Nonlinearcircuits publishes no current draw, depth or assembled price (it sells the DIY PCB and panel), and ModularGrid lists none