Soul of the Source of Uncertainty module is alive ! In the picture LFSR-circuit is connected and is working. My originally planned 17-bit LFSR-circuit didn't fit on this proto-board so I changed it to 16-bit version (two 4015 shift-register chips are enough for this). Length of this pseudo-random sequence is 2^16-1= 65535. If clocked with a 1Hz clock it repeats after 18 hours. I recorded two sound examples of the serial output of this LFSR. First one shows how it sounds when clock-rate sweeps from 0-34kHz. Second one shows how good white noise this module can generate when clocked with steady 34kHz. With this speed it should repeat after every 2s. If you listen carefully with headphones you can hear it repeating. Now I can connect the parallel output part of this circuit and check if my probability potentiometers actually work.