VCA, Waveshaper and LED-ring boards

A very minimal quad exponential VCA based on the V2164 (or similar). Meant to be mounted upright. I also made a similar four channel mixer that has only one output.

My waveshaper again, with saw, inverted saw, pulse, triangle, sine, sub osc with square and saw, two octaves.

LED ring prototype, to test if 32 LEDs is a viable option for the UI.

Noise and ring modulation boards

Ring modulation board

Three types of noise - white, pink and red

Three filter boards - Moog, Juno and JP

The three filters I've made - first the JP6-ish state variable filter, 10 modes in total.

Then the Juno filter, with selectable 12/24dB and overdrive (if I remember correctly)

And finally, the moog style ladder filter with 12/24dB and overdrive.

Three sample and hold board variants

First version, with large decoupling caps and lots of filtering, I think I got this design from the Fat Controller (http://burnit.co.uk/sdiy/index.php?page=fatcontroller)

Then a minimal, DIL14 version that just includes the S&H caps in the same space a normal TL074 takes. Sort of a drop-in replacement for a TL074, almost.

And finally an alternative version with slightly different routing. Not sure what will work best in practice so I made two variants.

Vocoder analysis/synthesis boards arrived

I picked up the vocoder analysis/synthesis boards yesterday. They look good as always, though I noticed some differences. Nothing to be alarmed about but I get why they are a bit cheaper than other boards:

- The silk screen is a bit misplaced on some boards
- The holes aren't always dead center on the pads
- One of the boards isn't completely flat, i.e. the fibre glass is slightly bent.

These are just very tiny deviations and well within what is acceptable, they just aren't perfect.

I'm very excited to get started on the build, to see if I've managed to get the circuit and layout right :)

Pro one mix and random board finished

Just finished the second board for the Pro-one project. This one contains the oscillator mixer, a modified noise circuit, a sample and hold part and the output buffer. There are so many ins and outs on the upper part of this card that I couldn't find room for the top right screw hole... Oh well.

I think it will take at least two more boards, perhaps three, to get all the necessary circuitry in place. And that excludes the front panel that will hold the pots and switches, and any output boards.

Pro one oscillator board finished

Just finished revision 1 of the Pro one oscillator board! It looks quite good and fits on a 10 x 8 cm PCB. It contains the CV-mixers and two oscillators. Next up is the audio mixer, envelope follower, reference voltage generator and noise generator.