Have built a Thomas Henry LM-VCO and in the middle of building an Eddy Bergman / YuSynth ADSR and a VCA. Hooked up to an AI Synthesis Stereo Matrix Mixer and Hexinverter Mutant Brain with an Alesis QX-49 keyboard and SR-18 drum machine.
What should I do with the last 10hp of my case?
Hmm, sounds like it might be worth me adding on another 24hp section to my case so that I can add a LFO. I’ll start with the filter, though - was looking at another Eddy Bergman stripboard layout for a VCF that ought to be quite manageable.
With 24 hp, you could fit a couple of LFOs and have space left for an attenuator. Look up attenuators, I’m sure Bergman’s site has one. It helps a lot for taming your modulations and you can fit like atleast two in four hp. A good LFO module size would be atleast 8 hp with two separate LFOs behind the panel. Some people can cram more in less space but ergonomics suffer. I think it’s plausible with to use a CD40106 (inverting Schmitt trigger oscillator) and a TL074 (output buffer ensuring 0-5v strength) with all the supporting circuits/jacks but definitely don’t take my word for it
That sounds like a plan.
I have some leftover TL074, a few CA3080, a few LM13700, and plenty of TL072 and basic CMOS chips and opamps, but I dont think I have the CD40106, but isnt a Schmitt trigger something that can be built entirely from transistors?
I’m thinking of making a 12hp generative module using arduino, DACs, and some code to operate as many CV controls as I can manage. Would be really cool to have it be able to implement a physical model algorithm for a guitar pluck or something, too.
Oh for sure you can use transistors. Slightly Nasty makes a full fledged VCO from transistors. So a great micro controller would be either the teensy line or even a RP2040 (I think that’s the designation it’s a raspberry pi based microcontroller.). Look up the Europi they have some great code examples you could look at.