Finally got all of the parts together to play my #synth #vcdo (voltage controlled digital oscillator)

It’s 1v/oct, an #attiny25 is programmed to respond to the incoming voltage and behave like a #vco

It also has a gate input, voltage controlled amplitude, voltage controlled waveform select, and voltage controlled tuning (I change the frequency of the internal osc on the attiny25), but in this clip, those last three functions are controlled by potentiometers

My 4yo is playing the keyboard

But… it looks a little slow. So I got out a known good working #VCDO and hooked it in instead, and I think I know what the problem is.

It looks like the fuses on the #attiny25 are incorrect and it’s using the 1mhz internal oscillator instead of the 8mhz one.

I don’t fully understand why that would give me the sounds I was hearing but maybe it’s an artifact of a slowly varying voltage going into a Class D chip amp. That’s just a guess though.

Alright let’s review what we are working on here because it’s been a couple of months. When I last looked at this a few months ago, I had just put together the new design of my #8bit #vcdo with my diy #EZMakeOven (a reflow oven for SMT soldering)

And because I cannibalized my test harness for another project, I hooked the new VCDO directly up to my #ArturiaKeystep

And it was acting really really weird. I could not figure it out. I inspected the board, but nothing made sense.