I received three doepfer modules today and the Ramdon noise is quite selfish in terms of I/O. So I decided to add another noise circuit into the system. It’s losely based on what can be found on the internet (Yusynth, Klein’s book, ect…) I just did my own sauce with that and add things. With noise circuit there’re two options : have matched transistor or trimers. I took the latter. I had to add a cap before the PINK filter because there was a huge offset and I didn’t want to add another trimers to the board. Other than that….not much to say.
One feature that I wanted and I’ve found quite nice (taken for the buchla 140 modules although it deals with gates) it’s the manual S&H button. Where you sample the input yourself with your bag of thumbs. That button can also freeze the clock and let the current voltage at the output until the button is released.
I’ve also added a Lag circuit after the S&H.
I started with this manual sample and hold which was quite simple and easy. However, adding a clock trigger was a bit annoying as the input must go to -12V to turn the transistor off (0 current must flow into the transistor’s base).
So, well I won’t re-invent the wheel a comparator with the tradditional JFET arrangement. I kept the manual triggering however.
Although, the buffering of the LAG s&H would be a transistor because of the verboard being limited spacewise.