Miasma is a pure analog oscillator module based on the Curtis CEM3340 chips used in legendary ’80s synths, with new & innovative signal patching:
We designed the Miasma Voltage Controlled Oscillator (VCO) to bring that classic ’80s synthesizer sound back to Eurorack modular systems. We just couldn’t find any currently available oscillators with the sound textures and capabilities that we wanted, so we had to design our own; and now you get to own one as well.
There are many unique capabilities built into Miasma that you won’t find in any other oscillator module, like the built-in patching and cross modulation structures that make Miasma so flexible in your rack. However, it’s all about the sound – so let’s start with some Miasma audio samples, before we go into the technical details of how we make that sound possible (best listening with Headphones!)
Jeremy S Cook writes on the Tindie blog:
Take a look at Tindie’s thriving sound section and you’ll see there is no shortage of people making their own electronic music. These devices take many forms, and one interesting take on sound creation is the OKAY 2 Synth DIY Kit. At face value it features 2 octaves of keys, a built-in amplifier along with a 1/4″ line out, and knobs to select the octaves that you’d like to play — but it gets more interesting under the hood.
Oskitone OKAY 2 from oskitone on Vimeo.
What makes it unique by today’s standards is that it doesn’t use any sort of computer or microcontroller, but instead produces sound using an LM555 timer along with other discreet components for monophonic sound. Given its small size, you could use two at once, perhaps combining them via the line out to be further modified in your synth setup!
In case you’re wondering, the original—or nearly so as it’s version 1.1.1—OKAY is also available. It works largely the same as the OKAY 2, but features only a single octave of keys, and doesn’t have an audio output jack.
From Brian Benchoff on Hackaday:
Before there were samplers, romplers, Skrillex, FM synths, and all the other sounds that don’t fit into the trailer for the new Blade Runner movie, electronic music was simple. Voltage controlled oscillators, voltage controlled filters, and CV keyboards ruled the roost. We’ve gone over a lot of voltage controlled synths, but [Tommy] took it to the next level. He designed a small, minimum viable synth based around the VCO in an old 4046 PLL chip
The circuit for this synth is built in two halves. The biggest, and what probably took the most time designing, is the key bed. This is a one-octave keyboard that’s completely 3D printed. We’ve seen something like this before in one of the projects from the SupplyFrame Design Lab residents, though while that keyboard worked it was necessary for [Tim], the creator of that project, to find a company that could make custom key beds for him.
Read more on the F0 on Tommy’s blog:
Darcy Neal will lead a workshop in Chicago on building your own synthesizer:
We’ll learn about some of the building blocks of creating a synthesizer using the 4046 VCO and the classic 40106 CMOS ICs. The 4046 is a well documented and powerful IC that can be turned into a modular synth voice with just a few added components. Participants will learn to solder together their own prototyping PCB, build a circuit on a breadboard from a schematic, experiment with sensors, and learn the basics about how to produce custom circuit boards using design software like Kicad and Fritzing. No experience is necessary, but basic electronic knowledge or a strong interest in synths will be helpful.