This project is for an analog VCO with termal compensation. It tracks quite well for atleast 5 octaves. I didn’t include a sinewave output, because all circuits I have found to convert a saw wave to sine are somewhat complicated and I wanted to fit the project in a eurorack format. The VCO has PWM, Exponential and Linear Modulation. It also has a sync input, which I still haven’t figure out haw to use creatively, so if you have any suggestions your welcome.
Here’s a video for the project:
Yo! Nice!
I actually posted about your project here before: Non 3340 oscillators - #128 by BlackDeath
I’m actually really hoping to put together a version of your spring reverb with the feedback, but in your video you mention the possibility of runaway feedback starting a fire and wasn’t entirely sure how serious you were about that.
Thanks for spreading the word! This is actually a new oscillator project. This one has PWM and triangle wave output, so it’s a bit more complex, but I really like PWM and I wanted to have such oscillator. About the spring reverb, I was joking about catching fire haha. The problem is that the input is not buffered, and if you don’t connect it to anything it starts to self oscilate. It shouldn’t be possible to cause damage, because the maximum voltage is limitted by the diodes. If you buffer the input with another opamp this problem won’t be present but I thought it’s not big of a deal. You can remove the part that is for the fuzz type distortion with the diodes and buffer the output with the positive input of the opamp, you get one free opamp, so you can use that to buffer the input
Anyway this oscillator uses the same schematic for the 1v/octave convertion as the previous one, but the oscillator core is a bit more sophisticated, should be more stable. And also there are the parts for the convertion to PWM and triangle
