this post was submitted on 21 Apr 2024
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synthdiy

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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?

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[–] [email protected] 3 points 6 months ago (1 children)

Actually, if you could squeeze in 6 hp filter and 4 hp lfo that would be cool too

[–] [email protected] 1 points 6 months ago (1 children)

a 4hp lfo would be quite a challenge for me, but i’ll look into it. from my understanding, the lfo would let me tweak the vca parameters and it could be used as an fm input for the vco?

[–] [email protected] 2 points 6 months ago (1 children)

If it’s fast enough it’s good for FM, but it can also wiggle that Pulse Width Modulation input. Can also help with lasers/sirens in the v/oct input. Can also wiggle a filter cut off. LFO’s are awesome <3. But if I had to choose in your set up, the filter will make the biggest difference to your overall sound. Your ADSR envelope will do the heavy lifting, especially with that really useful inverted output

[–] [email protected] 1 points 6 months ago (1 children)

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.

[–] [email protected] 2 points 6 months ago (1 children)

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

[–] [email protected] 1 points 6 months ago* (last edited 6 months ago) (1 children)

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.

[–] [email protected] 2 points 6 months ago

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.

[–] [email protected] 3 points 6 months ago (1 children)

No cap, a filter would be pretty choice to finish you out with a classic mono synth architecture

[–] [email protected] 1 points 5 months ago (1 children)

Wish I could upvote this twice lol.

[–] [email protected] 2 points 5 months ago (1 children)

I take it you got a filter buddy?

[–] [email protected] 1 points 5 months ago

Unfortunately, not yet, my synthdiy skill is still introductory. I do have an idea of what filter I’d like to build (Steiner-Parker, but it’s in a queue with a slow rate of dequeue, right now :/