2 channel analog video (transistor based) noise source, with some nice additions..
…such as offset and volume controls, highpass filtered outputs and a comparator (with switchable noise channel) to create very interesting chaotic textures (from starfields to blizzards)
2x noise channels with Offset and Volume pots
1x comparator (selectable noise channel) with Bias pot
2x offset noise outputs
2x filtered outputs
1x comparator output
Intermediate. All resistors are mounted ‘standing up’ and the pcb is tightly packed!
This project is open source.
You can use the schematic to make your own boards, but please:
-Mention my name “Reverselandfill” or “M.Verhallen”
-Only do non-commercial runs. Private use only.
BOM and build files:
BOM v2 has 2x 499r resistors instead of 1k trimpots,
for the gain of the noise transistor.
The 2 trimpots (pcb version 2.2) set the gain amount of the Noise. The trimpot closest to the power header is for Noise1, the one above that for Noise2. Turn the screw clockwise for higher gain. To get the best setting, patch Filtered Noise1 to the RGB encoder and turn the volume Pot of that channel all the way up. Now turn the screw Clockwise until you see a nice noise image with lots of detail. If you set it too high, the noise signals clips too much and you will see no variation in the voltages.
Do the same for the other channel (which looks different, because of the filter values. more stripes instead of dots).
If you see too little noise output, it is possible that the noise transistors have a larger negative offset. To fix this, change r34 (Noise1) and/or r37 (Noise2) to a lower value, such as 10k or 1k.
Alternatively, you can swap out the transistors.