Hey, this night I have build a line level master output module, really usefull for playing stereo with my system!
The circuit come from this greatfull page :
https://sfcs.neocities.org/module/SFP09/
Nice Day to all!!
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I found these micro-modules from Thonk and tried if I could use that ĀµVCO to make a 3340-oscillator. Well, it works and sounds what it should and I could get it reasonably in tune. Only problems were my incapability of remembering how polarities of power voltages to TL072 and TL074 go. First I wired them backwards to TL074 and frying it. Then I reversed them, but didnāt remember to change them also to TL072 which was now wired backwards, soā¦ After changing that I noticed, that my other trimmer pot was broken also. They, and TL072 as a buffer for them, are for getting +10V and +5V voltages to pots controlling coarse and fine tune and pulse width. Pulse width with this ĀµVCO is controlled by 0-5V, but now the PWM-knob gives 0-11V due to the broken trimmer, so it works kinda, the range is just a bit messed up. The TL074 sums that voltage from the PWM pot and PWM jack, which is halved, and inserts that to the PWM-input. Point was to be able to adjust the PWM pot to middle, giving 2,5V and having 10V p-to-p lfo-signal in the jack to have PWM ranging from minimum to maximum without clipping. Well, now it just requires the PWM pot to be in somewhere not-in-the-middle. Maybe Iāll buy a new trimmer pot and change it, at least I was foresightful enough to put the trimmers in the edge, so I maybe donāt have to disassemble the whole thing.
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I made the Mini ADSR! Some very ugly soldering since I put in fake transistors the first time and had to redo them, but the blinky lights work!
Huh, thatās a new one. Tell us more!
(I mean, people faking expensive power transistors is nothing new, but the #1157 uses 2N3904s or similar that cost nothingā¦)
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It was my fault, I guess, I ordered some "2N3904"s from AliExpress, but didnāt take a closer look until after Iād actually soldered them in all over the place. In tiny writing that smudges off very easily, it says BC547ā¦ which has a different pinout.
Today i made some wood cut, mastic, paint ā¦ to make a replica of the Portal Gun from Rick & Morty, with a little circuit for some nice light. and a false digital fx (with a stencil tricks and red thin plastic)
iām waitting for an ISD1820 order to add some sound inside (like in my diy Flux Capacitor replica )
Lot of fun !
Message from dimension C137 
Hereās a new topic about details build
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New season starts on June 20!
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Im up to a decent point with my case, ive got modules screwed in and PSUs mounted now I just need to figure out where im going to mount the buss boards.
Then its just the backboards and some holes for the power connectors =)
I should probably test the rest of my 3D printed modules before plugging things in for good XD
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I have a first working version of my polysynth. It has 6 independent voices, from left to right: MIDI controlled http://lookmumnocomputer.discourse.group/t/raspberry-pi-pico-dco, ADSR, VCA, mixer and PSU. ADSR and VCA are capable of eight voices but for now I only have the DCO with six voices at hand. It is still missing a VCF, LFO and so on but already has a quite nice sound. So next will be a board with VCFs and controls of the ADSRs need some more fiddling. I think itās time to think about some casing.
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This is how it sounds, some Bach:
It is just the DCO, ADSRs and VCAs, no filter.
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This is quite the achievement. Sounds good too!
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Iāve had my case built for a while but as Iām waiting on two more packages to complete all my modules, I thought Iād put the power in today. I couldnāt decide if I wanted to have the power on the bottom left or bottom right so I decided to put a port on both sides.
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Iāve been at this on an off for months, constantly blocked by sourcing little bits here and there, but Iāve finally got my first fully DIY, stripboarded, scrap-panel module sitting in my scrap wood case. Feels good man.
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Congratz!
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Finally finishing up a very important piece of the rack, the dual quantizer.
Update: getting close now, time for a beer and code.
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Got the TLC5940 led driver and the MCP23017 to play together nicely. Guess what this will beā¦ eventuallyā¦
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That is blinky. I dunno what it is but I love it. 
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What could go wrong?
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Itās anticipatory. Itās definitely going to go wrong.
Update: it went wrong
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