After a successful prototyping session yesterday with the VEB,
I came up with a new project called “SNOW”.
The idea is to make a Video Noise Source module .
In the current schematic not everything is connected yet and some values and voltages will be changed later. Work in Progress!
Current features:
analog transistor noise
highpass filter
bias control (very rough state, this will be a trimmer on the back)
gain control (now it is just a attenuator)
Upcoming features:
comparator output (possible with CV control over bias)
more outputs with several filter configurations
…and more
The Video experimentation board helped me quite a lot. so many of my ideas get stuck in the breadboard stage. It really is helpful to have all those video requirements at hand.
So my Sunday was very productive .
The comparator stage is not working correctly yet . But maybe I have to use a specialized IC instead of this lm6172 setup.
When I patch the noise output to the Cadet Hard Key, it works beautifully. (which uses the LM361)
Afterlife Laboratories has a noise generator as part of their “Video Motion” module, but it’d be good to see a standalone noise generator on the market
It was already snowing here today, so I did some more work on it.
I had some new ideas about the filter sections. to filter after the amplification, and have several configurations. (lowpass, highpass) I still have to test the values, but it will become something like this.
I might make one simple noise source, and later a bigger extended version
This way I can release the first SNOW for the holidays
The simple one will have 2 pots (gain + comparator threshold), 4 output jacks and maybe a switch
*which noise is routed to the comparator. filtered of white. I have to test if this is interesting enough.
else it may become a jumper setting.
The comparator section is working in the simulation:
Update:
I decided to make it a dual noise source. 8HP
That way you can have a low frequency & high frequency noise output at the same time, in my tests this gave interesting results. (snow vs. blizzard)
Features:
2x offset pot
2x level pot
1x comparator pot
1x comparator source switch (noise1 or noise2)
2x noise out jacks
2x filtered out jacks (2x highpass filters with gain settings)
1x comparator out jack
Unrouted pcb:
All resistors are vertical. another tight fit!
there are 2x trimpots for the noise gain, as this might vary per type of transistor. I use 2n3904.
I liked war of the ants but it was a bit expensive and large for what I wanted out of a noise source. This feels more in line with what I’m looking for.
Amazing!
Count me in!
3 filters would be even crazier, to send the related outputs to RGB channels.
Another idea: jumper after either noise1 or noise2 and before the switch to use an external signal on the filters with an expansion panel
