Custom synth enclosure – Part 1
With the main modular audio chain assembled, and (almost) playable from a 37-key piano keybed, I started to turn my attention to designing an enclosure to hold all the components of the synth together…
Dual ±12V 48W linear power supply from single-sided DC input
My Eurorack-compatible synth project requires a ±12V power supply. I also wanted to use an external “power brick”-style AC-DC converter to handle the mains power. I developed my own secondary DC-DC power supply with two LDOs, a Ćuk inverting regulator, and a power distribution bus to clean up the output of the power brick and generate the dual-sided power supply required by the rest of the system.
Op amps!
There are so many op amps to choose from…. which one should I use?
The GS-101 analog synthesizer project
Ironically, since I’ve spent so much time working on this project, I have not posted about it much—but I’ve spent a huge amount of my free time in the past two years or so building a complete analog synthesizer. From scratch. And now it’s really starting to come together!
Gremblnote Application Note GN-0001: OTA-based Automatic Gain Control (AGC) Circuit
I developed this automatic gain control (AGC) circuit to compensate for the -3 dB gain after each filter stage in a 2-stage, 4-pole voltage-controlled filter (VCF). I’m posting this because it was surprisingly difficult (rather, impossible) to find a low-distortion operational transconductance amplifier (OTA) driven AGC schematic I could use directly.
Precision current reference – part 2
In Part 2 of the Precision Current Reference build, I assembled and calibrated the instrument and tested it out.
Precision current reference
A precision current source like you’d find in an SMU would be a very helpful tool for some of my other projects. But an SMU costs an arm and a leg… my needs were not so great. Could I make what I needed without breaking the bank?
Audio hardware Development Breakout Board
Over the past year I’ve gotten into building modular synth components. There’s a lot more to share on that front; I’ve put together several modules and have a plan for several more to go into an integrated system. The relative complexity means there’s a lot to write about, though, which has made me keep putting it off…
In the meantime, I completed a smaller project this weekend—a breakout board that makes it easier to develop audio circuitry on a breadboard.
What is SaaS?
I recently got in a discussion on the Slack associated with the Hacking SaaS substack. (Which if you’re in the industry, you should definitely read!) The question was about what kinds of tools you should feel comfortable using if you’re an engineer at a SaaS business. The conversation then turned to the nature of: what …
Luminous Gates
In a recent blog post I described building a more powerful EL-wire driver based on the 555 timer. That was in service of a small art project which I finished last week, “Luminous Gates.”