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  • 2 min read

ADSR Envelope Generator

I recently got PCBs back for the second iteration of the ADSR envelope generator. I was originally inspired by the designs that Rene Schmitz published, which have their origins in a 555-based circuit by Johnathan Jacky (see the notes in the YuSynth version). The 555 core is very clever and encapsulates the state logic in the 555's internal latch and threshold circuits. I've gone through a few iterations to get to this version, but I think this one is really solid and adds something new (at least as far as I can find for the 555-core circuits): a trigger. More below the fold.

  • 1 min read

Updated Gate Delay

After getting the PCBs back for the first version of the gate delay, I decided that there were two features I missed: split controls (CV and pot) for the delay itself and a trigger (short pulse) output.

  • 2 min read

Linear to Exponential Conversion

A couple of designs now have required linear to exponential conversion for the control signal, so I've added it as my first "building block" note in the reference section. This version is the one of the more sophisticated ones, including buffering and temperature compensation, so it's suitable for designs requiring V/oct tracking.

  • 3 min read

Dual Gate Delay

When I started on the ADSR, I looked at a few commercial examples in addition to the DIY versions. While watching a couple of Monotrail Tech Talk videos (part 1 and part 2 - highly recommended!), the Erica Synths Black DADSR EG caught my attention with some interesting extras, and one of those was the delay.

  • 2 min read

Mixer+

Continuing on the migration and clean-up of my modules, I refreshed the Mixer+ design and documentation. This was a more involved effort: I populated a second copy of the v1.1 PCB for my "production" case, and while I was doing that I ran into some issues.