These are my build notes for the nonlinear circuits "stochaos" module. It's a 8hp eurorack. STOCHAOS...... It's a random rhythm pattern generator or sequencer which produces gates and control voltages There are just two inputs ; IN & RST Everything else is an output Links + Wiki + BOM.. + CD4028 BCD to Decimal converter + Flip Flops - an introduction + CMOS & Lunetta synths This is a decent sized build using 2 PCBs Start with the ICs and transistors. The module uses a lot of cmos CD4070 x2....... XOR CD4040 x2 .... clock divider CD4040 clock divider's outputs feed the four binary inputs of a CD4028 BCD to Decimal converting chip, creating pseudo-random sequences, depending on different CD4040 outputs feeding different CD4028 BCD inputs. "The circuit can be easily modified by replacing the two 4070 XOR chips with two 4081 AND chips (or any other 4 channel two input logic chip – OR, NAND, XNOR, NOR). I might Build both versions ....the one-gate-at-a-time version tends to get a much faster clock signal" (Andrew F). CD 40175... Quad D-type Flip-Flop CD 4028....... BCD-to-decimal Decoder Resistors Pink noise level : *** 1M-10M? x 1 ........................select for pink noise level . ................ im using a 10M RL (LED resistor) x 9 ..............select resistor to suit LED brightness (prob 4k7 to 10k) ..... im using 4.7K .... power rectifier BAT54GWX Diodes LL4148 5mm LED for chaos circuit on top PCB, any crappy LED is fine but high V-on is good so a blue one if you have it. headers to unite the two PCBs switch SPDT - on-off-on Jacks 3mm LEDs x 8 ....Up to you, diffused lens are easier on the eyes. Square hole = anode I always do these last. You're there First tests. The LEDs light up. That's promising. the input needs a SAW or SQUARE wave Sine & Tri waves don't trigger the module very well. ----------------------------------------------------------------------------------- You can find more NLC builds here. http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html --------------------------------------------------------------------------------------