Demo: http://misw.us/909NoiseMod.wav
The first clip is the shared noise source, it loops a couple of times, then there is a pause and the same sequence is played with the secondary noise source. Note the "swish" sound of the first clip, it is gone in the second clip.
I am offering just the PCB and 4006 shift registers.
price: $15
Shipping: US 3$, rest of the world $7, I will ship these with knobs if you have ordered those for free
Ordering is closed
You can order boards here: https://www.oshpark.com/shared_projects/uchHoYHk
Installation: Remove ONE side of R208 (the side connected to pin 9 IC33, the other side is connected to R209) and solder a wire from the NOISE output of the new noise board to that leg of the resistor.
Connect +15V and GND to the noise board wherever convenient
BOM:
CD4070 x 1
10K resistor x 3
33K resistor x 1
47k reistor x 1
1N4148 diodes x 2
100n ceramic cap, 2.5mm spacing x 1
100p ceramic cap , 5mm spacing x 1
4.7 uF electrolytic capacitor > 25V x 1
100K reistor x 1

