Here’s a comparators module from YuSynth, in Kosmo format. I bought the PCB from Soundtronics and put it behind my own panel. This module has two comparators, each of which takes an input voltage and turns on a gate whenever that voltage is above a threshold. It also puts out a trigger on one output […]
Read More YuSynth comparatorsThis is the Barton Musical Circuits BMC21 Full Wave Dual Rectifier in Kosmo format. It’s built using a PCB I bought from Barton, behind a panel I designed and had fabricated. It’s a kind of wavefolding circuit. An input waveform is AC coupled, a DC bias is added, and it’s rectified, so anything below 0 […]
Read More Barton Full Wave RectifierKosmodrome has a low frequency oscillator, the MFOS voltage controlled LFO, with a modification to give it a sync input. A pretty powerful module. I don’t really need more such fancy LFOs but a couple of basic, non synched, non voltage controlled LFOs would be useful. So this is my new Kosmo format dual LFO. […]
Read More Kassutronics Dual LFOAn all pass filter sounds rather like an in joke: A filter that passes all frequencies without attenuation. A piece of wire, in other words? But no: Filters change not only amplitudes in a frequency dependent way, but phases as well. An all pass filter just specializes in the latter. Sine waves far below the […]
Read More Voltage controlled all pass filterThis is a Kosmo format version of René Schmitz’s YASH sample and hold. Sample and hold is something used in a lot of contexts other than / more commercially important than synthesis, so there’s such a thing as sample and hold ICs that are readily available. This uses the LF398 chip. All Schmitz’s circuit does […]
Read More Yet another sample and holdThis is a ring modulator in Kosmo format. No, really. A real ring modulator. There are lots of “ring modulators” out there that are in fact no such thing. They have similar behavior, and may arguably be better in some ways, but they’re more properly called four quadrant multipliers or balanced modulators or something, whereas […]
Read More CGS (Ken Stone) Active Real Ring ModulatorThis is an envelope follower (EF) module in Kosmo format with mic and instrument preamplifiers. I looked, in simulations and on the breadboard, at several envelope follower designs (you can read about some of that by following the envelope follower tag) and ended up deciding to go with a design based on the ARP 2600 […]
Read More ARP 2600 (-based) envelope followerLook around the synth DIY world and before long you’re likely to find a circuit containing something like this: This is an attempt to give voltage control to a circuit, using a vactrol. A vactrol is a light source (classically a little neon or incandescant light, but these days an LED) and a photoresistor butted […]
Read More How to vactrolI built a stoopid little op amp tester. Turns out those two TL074s I assumed were fried after I reverse powered them seem to be okay. Good enough to light LEDs anyway. https://gitlab.com/rsholmes/opamptester
Read More Op amp tester
Analog Output 