Zlob Modular Entropy Expander Random Voltage and Noise Source

The Entropy+Expander packs together some of the most random voltage options in 6hp. It provides a controllable “Glide”(slew) out for the S/T\H, a comparator with a controllable rate(“Thrsh”) of random gates(“Rand Gate”) out with an input to compare other waveforms(Comp In, inserting a cable into here breaks the white noise normalization), and high pass filtered white noise resulting in approximate “Blue noise”(+3db/octave) and “Violet noise”(+6db/octave) outs.

The unique part of the circuit is a voltage controlled A/B switch thats normalled to the “Rand Gate” out that’s switching between the S/T\H out(left Blue led window)and Infra out(right Red led window), the Glide control also effects the S/T\H coming out of the switch so you can get really random results from the “Entropy Out.” Inserting a cable into “Switch CV In” breaks the random gate normalization and lets you toggle between A/B(left S/T\H out and right Infra out, indicated by the led windows) with your own gate or trigger.

There is a jumper on the pcb to select if you want glide on the s/t\h at, Entropy out, or un-slewed operation. There is also a trimmer for setting the amplitude of the incoming signal at “Comp In” which sets the frequency range of random gates. This may have to be adjusted depending on your Entropy version.

The random gate range can also be set up more as a noise oscillator by turning the pcb trim(clockwise) up or it can be set so random gates are extremely slow(trim counter clockwise) with minutes between random gates.