Breadboard Synthesizer

About the only thing more fun than fiddling with synthesizers is building them. Or at least taking a flying stab at it. Now, I’ve certainly built my share of fairly basic synth parts… mults, an AS3340 VCO, amps, and so on. I’ve even recently made a perfectly adequate Eurorack-compatible power supply. But I decided to kick it up a notch a couple months ago when I built this:

Maybe “decided to” is a bit strong. It just sort of happened, after having watched Moritz Klein’s superb DIY VCO series, his filter, his arpeggiator, and so on. Would you be surprised to learn that synths on a breadboard connect just as easily as synth modules? Derp.

By the time I puzzled out a CD4017-based 16-step sequencer I realized I had something pretty nifty on my hands. Add an envelope generator and a simple clock and you have more or less all you need for a fun little groove-box—all crammed into a series of breadboard knit together by hot glue and tangle of wires. I will be spending some time trying to turn it into a standalone semi-modular sort of deal, and perhaps even a synth module. It might lose some of the rustic charm in the transition, but ought to be a bit sturdier and easier to control—at minimum.

I’ll see if I can’t post a few more things about this thing. Certainly some schematics are in order. You’ll notice perhaps that while the quantizer bears some resemblance to Moritz Klein’s it is also a great deal different. It is perhaps my only true innovation (for lack of a better word), as much of what you see here is cobbled together from datasheets and various schematics floating around.

Certainly I’ll be documenting the journey from breadboard to enclosure in the coming weeks/months/years. It’s something that’s occupied my thoughts a lot lately, and will demand a willingness to launch myself pretty damn far outside my comfort zone’s tight radius. Stay tuned, and carpe diem!

A Brief Sojourn in the Land of Synth DIY

So I’ve been a little low-key with the whole blog thing, of late. Sorry, team. We crusty old-timers need plenty of beauty sleep and smoothing down the wrinkles erupting all over my body is a time intensive process, especially given that the joints are taut as bowstrings. I blame the microdoses of Viagra in the drinking water.

But in my free time, between brushing cat hair off my dentures and filing down my corns, I have embarked on a rather interesting journey: I’ve decided to pick up synth DIY as a hobby. Yeah, another one, amirite? The learning curve has been fairly intense and quite intimidating, and, as I have long maintained, have no idea what I am doing. This mantra of mine is especially true of electronics, where my experience is limited to some rather weak Arduino and Raspberry Pi projects. However, after a few frustrating months, I have breadboarded a VCO! See above (the blog consultant I spoke to said to put a picture towards the top, even if it is just a cat picture, because nobody reads anything anymore.)

This is a fairly simple VCO, if ever such a thing can be said. In fact, it is somewhat lazy, relying largely on the AS3340 (a knockoff of the famous CEM 3340) which requires very little in the way of effort to get sound out of it. Well, sort of. If anything, it is a godsend that it takes care of the 1v/oct tracking for you, which is one of the tricky bits of building an oscillator. This design is based on a subset of the AS3340 reference schematic, which is pretty straightforward after you spend a couple semesters in trade school learning how to read schematics. Just kidding—a few hours of Googling is enough to get up to speed.

Naturally, if you want to get up and running without knowing what you are doing (an approach I often endorse) there are some pretty excellent tutorials from LookMumNoComputer (perhaps most famous for his Furby Organ, which is probably the niftiest thing on the Internets so far.) If you are going down that route, be aware that he is using the rather more expensive CEM 3340, so be sure to pay attention to the values used in the AS3340 reference schematic, if you are an old cheapskate like me.

Anyway, whatever your approach, it won’t be long before you’ll end up with some dope, clean waveforms, as pictured here:

See the blurred oscilloscope in the background? Cool.

Do the kids still say “gnarly”? Because I think that looks gnarly. In any case, expect some more writeups about this in the coming months. Who knows? Maybe someday I’ll have an Etsy storefront and some PCBs for sale on the Thonk or whatever.

Carpe Diem!