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…
diy
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.
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.
An EL-wire driver based on 555 timer
I built my own circuit to handle conversion of 6 VDC power from the batteries to the 2 KHz AC power required by EL-wire.
3-D printed case for Raspberry Pi & LCD
I recently designed a custom case to fit a Raspberry Pi 4 and a 7″ LCD screen. I wanted a small tablet-like computer I could set up to look at while seated at a table, or standing at a counter in the kitchen.
Building an embedded device for sailboat racing: installation (take two) - success!
Time to wrap this up… I was, in fact, able to get this successfully wired up and mounted on the boat! All in all, I had a great time making this project and learned a lot.