heyy the VCO PCB arrived last weekend and I soldered everything together - and everything works like a charm, yeah! It is a huge mess of cables because I have so many CV inputs and knobs on this VCO. But I did a lot of improvements since the first, non functioning version:
connected Eurorack plug in the correct order lol
easy switching the audio signal offset (±5V to 0-10V) – with the help of @clarionut, thanxxx!
first time trying an 1mm thick aluminium panel sprayed black with white Edding pen (and a finer pen)
AS3340 timer capacitor switch from 1nF to 100nF for LFO capability
triangle to sine converter with the help of @analogoutput thank you both!
used jst 2mm connectors to connect each front panel component for better reparability & to prevent bending soldered wires (it was a huge load of work tho)
used metal angles from an old construction toy set to screw together the PCB and the frontpanel.
its called FUSION VCO, because I call my whole synth FUSION CORE.
I just need to calibrate the 1V/Oct input with my Beatstep Pro, didn’t find the right spot with the tuner trimmer and high frequency trimmer yet.
My next steps are manufacturing two other VCOs (takes one day each) and then I’ll do a LM13700 filter…maybe also a knob-adjustable signal-attenuating module for audio output to headphones & my audio interface.
These modules look interesting! Do you have schematics of these Electro Harmonix effects modules, as well as the Korg Minipops? I have a drum module and one or more effects (or filters) on my want list, so maybe these could fit.
This was an interesting discussion and it made me revisit my Digisound 80 VCO. Now it has a new front panel with both ±5V and 0-10V outputs for each of the three waveforms. I also revisited the sync options - +hard and -hard never really worked well needing very high level signals to have any effect, so I reverted to the simpler datasheet circuit for a single hard sync input. Here’s the new version:
Thank you very much! That Effects Layout page looks very interesting, have not heard of it before. I will probably make an effects module like you did.
It’s been nearly five months that I haven’t built anything as I was busy, but I managed to find some time for the following.
I finally found the parts that I had misplaced and built a second power supply to run in parallel with a hefty 2.5A AC/AC transformer that I bought some time ago. A 2.5A slow blow fuse did the trick with all the inrush current that I had troubles with in the past, so now I think that I got plenty of juice to fill the rest of the case. I also tidied up a little the spagetti of power cables at the back (a mix of JST-XH and the regular 10 pin box connectors).
I resolved all the issues I had with several modules, most notably the David Haillant VCA where I had a bad LM13700.
I did some module maintenace, cleaned the flux I had forgotten about and hot-glued the boards to the panels in cases they were wonky.
And finally, with the addition of the Chaos module I am officially half-way through the 150cm case.
I have been very curious about this project and been wondering whether anyone had built this apart from @benjiao ! Perhaps you can share the details and your experience with it?
I build this granulat in 2018 from Notes and Volts: Build the Auduino Granular Synth - Part 1 .I always liked the sound of this module. I only missed cv. The code is original from note volts, I pulled it out of an old box because I hardly used it at all and decided to connect a jack to the middle pin of each potentiometer. I have to make precise documentation about the switches because I connected them later, at the beginning they were not supposed to be there at allThese are two oscillators that have tune control (I connect cv sequencer to them) and timbres where I connect EG. The middle one is a mix (I didn’t connect a jack to it), one with a switch I connected two tune pots together, the rest, sorry, I have to take it out and see. I wanted to use it already and I didn’t even make documentation.
I made a test box for my synth module building. That way I can test them while building on my dinner table, without the need to hook things up to my case.
With the build-in breadboard, jack sockets with LEDs for input signals, pin headers, and amplifier and speaker, I can make my build progress much easier for myself.
Delay with 2 bit bitrate and samplerate of 16kHz divided by some integer, or delay times of about 270 ms to 1.2 seconds, when output doesn’t really sound a lot about what went in. Mozzi-library eats most of the ram, so I had to work with 512 bytes for the delay buffer. Programming my own library that does only the minimum would probably allow even a full kilobyte for the delay buffer. But would it be easier to try to do it from scratch or try to make my own extremely minimized version of Mozzi, as it already has nicer analog reads and that two pwm-output.
Listed from right to left I have a linear power source from the MFOS 12Vac wall wart schematic with + and - 12Vdc. Then it’s a dual 1 to 2 multiple, with a dual 2 to 1 mix. Followed by a dual shape dual range twin lfos (David Haillant) with the twin transistor based vcas (Moritz Klein). Then it’s a dual AR generators (LMNC) with Rene Schmitz Fastest Envelope in the West. Followed by the trusty Rene Schmitz Ms20 clone based mostly off the @EddyBergman design. Also by way of Eddy Bergman’s synth diy page I have the Thomas Henry 555 VCO. I meant to make the pair but couldn’t get number two running before I decided to scrap it and go with a simple 4046 setup based off the Hackaday page and Kristian Blasol at Modular in a Week. Not volt per octave and limited range but a perfectly good sync signal for the Thomas Henry and it also has a sync type input to play with. I’m really liking this setup. I plan to do a jam at a party next weekend so I will post a recording on sound cloud.
Some time ago, my build progress got stuck with half-finished modules, having small bugs or glitches. I decided to step back for a while and first build a desktop tool which supports development and testing my modules.
The case is designed with Inkscape and made of MDF with Acryl front panels, which happened to become modular. Fortunately there’s a laser cutter in our makerspace which made prototyping a breeze. I had a spare 8x jacks board from #1222 Performance VCO at hand so it ended up with 8xIn/Out:
