Molecular Relaxation Simulator

A complex slew and envelope generator. The concept came from a 1970 paper, An electronic simulator for transient processes, a circuit meant to simulate the electrical properties and responses of biological and synthetic macromolecules in solution when subjected to high voltage pulse signals. The input is sent into two channels whose amplitude (LVL) and slew (RATE) are set independently, the slew voltage controlled (CV1 is normalled to CV2). The two channels are summed and difference-rectified: SUM and DIFF are on the panel, and both are mixed for the main OUT. A switch per channel chooses its slew range by its capacitor: high (10 nF), mid (100 nF) or low (1 µF). Fed from a sequencer or an LFO it shapes slews; fed gates it works as an envelope generator. Every control affects everything else: once you get it, it dials in a huge variety of morphing envelope and slew shapes, even ADSR envelopes or reversed ones.

Key features

• IN, CV 1 and CV 2 in (CV 1 normalled to CV 2); DIFF, SUM and OUT
• LVL 1, LVL 2, RATE 1, RATE 2, CV1 and CV 2 knobs
• Two RATE switches, MID / HIGH / LOW, one per channel
• 8 HP; Nonlinearcircuits publishes no current draw, depth or assembled price (it sells the DIY PCB and panel), and ModularGrid lists none