3340 VCO Schematic for PCB design

omg… and you can buy green plasti-dip too :heart_eyes:

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If you’re careful it works on toggle switches too.
Oh and @Dud it comes in blood red and black too :grin:

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No way, I love big buttons (… and another little detail so, I don’t have a printer)
:grin:

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Go on! Dip a switch. You can thank me later :wink:

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I suppose I could do better…

May I introduce big bertha >.>

PS… An update on the front panel ;D

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…too …many …big knob jokes… Must resist…

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If anyone has been looking on GitHub recently they will see that I am actually working on a ~20cm module with a gigantic 3D printed knob on it. Stay tuned!

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:eyes:
stays tuned

Also, that face panel finished production last night! Probably be here next week or week after next (I’m sure with the holidays it’ll take an extra week, but DHL is surprisingly fast here)

EDIT:

Something I randomly thought about too… the reason I made this extremely thin/tiny knob caps to start with, was to have that nice fitting form to go over the shaft :wink:

Figured it all twiddly-dee after that
Critcal dimentions were:
6mm +0.3 shaft (compensation, applies each time)
2mm +0.3 rise
1.55mm from one side (for the flat bit)
so you should have ~4.55mm of empty space inside

P.s. I found that some fit perfectly tight, some just fell off… so I’d call it dead middle TBH
This is where that dab of hot glue is a nice touch ;D

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for the latest progress :wink:

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ooooooo heckin yesss!
(2800 lines o.o)

Also… after LMNC did the last jam and had tetris in it, was stuuuuuuuuck in my head, so I did this little diddly bit last night, I had to share because this morning with fresh ears… omg, I’m really proud of that ;D (day 2 of owning a drumbrute, loving it btw)

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1k op amp resistors in Falstad and 100k in KiCad, are you trying to upset Matthew Skala? :laughing:

It’s a cliche of Eurorack design to have an inverting op amp with 100k resistors at the module inputs, in order to expose a 100k input impedance to the outside world; and there may not be much way to avoid that. … But these high impedances should be avoided where possible, among other reasons because of an effect called Johnson noise… It’s usually better to aim for lower component values in op amp circuits in order to bring the level of Johnson noise below that of other noise sources. … as a rough rule of thumb, I usually aim for impedance more like 10k or 20k on any op amp input where I don’t need to go higher. Lower is better for noise, but trades off power consumption and loading of the op amp and whatever is supplying the input. (Design mistakes in synth schematics - North Coast Synthesis Ltd.)

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Yooooooo I just had an idea…

I know this would waste kinda waste space… but hear me out.

Okay so I’ve made this module, completely modular right? Well that’s not just the jacks and knobs…
That’s literally, I made the outputs as pinheaders for a reason. easy pinout, also for a reason. multiples of 3 and such…

Okay so, why not just make a new proj, start the schematic off like you would anything else, but it be a buffered pot, of course the reason here is obvious, but like, you could have the circuit include toggles for each “input knob” (knob to be controlled) so that you can gang them all together, or toggle off one or which ever.
Effectively having “master knobs”.

The schematic shouldn’t be hard, as you’re just using the opamp to mirror what the master pot is doing to the slave pots.

So the design, you go to pcb new and make a new PCB, maybe drop the footprints or whatever, but don’t make a design yet. Save and exit.

Open that PCB file in stand-alone and append the board, using the previous board design (I did this for my front panel design so the stuff lines up, I’m sure it’s obvious knowledge, but for the sake of anyone not in the know who might read this later on)

Delete all of the contents within the edge cuts except the mounting holes, then save it.

Close that down and go back into the project as a whole, and go to pcbnew to edit your new design so that it fits within the footprint from the main vco board.

FEW DESIGN THOUGHTS
You’re going to have 1-5 (or however many you’re building) inputs, so that all of the boards go to the mixer module, rather than directly to the remote boards. At least this makes use of the space that isn’t taken up with circuitry, so that’s a plus

Secondly, if you were so included, you could have a toggle that switches between the original knobs so that each one can be controlled independently, or to the master knob.

Could also leave the tuning knobs out of the circuit, because it’s unlikely they’ll all be similar in tuning that way, anyway.

Apologies for the book, but I wanted to write it down somewhere that wouldn’t just vanish like my ADHD brain XD

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This is reminiscent of the Moog 621a and 621b: The 621b was a VCO, somewhat stripped down in its controls to fit in a module about half as wide as the full featured 621 oscillator, and then the 621a was an oscillator driver module with a full set of controls that would link to multiple 621b modules. So you could build a voice from several oscillators and control them all from a single set of knobs and jacks, and it’d take up less space than multiple 621 modules too.

Sam apparently had/has similar intentions with his VCO, it includes a link header for a controller, but the controller doesn’t exist (yet).

I’m working on a related idea but not ready for prime time…

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Figured while I was waiting on the Front panel, which shipped today (Yay!! Should be here by next week)
and while trying to prevent myself opening and getting into building the VCOs ( the final boards made it today… also yay!!) while the kids are still here (ex is sick, so I’ve had them the last week and change)…
Thought I would design a cable holder (didn’t really take much effort TBH, it’s just like… 3 moves in fusion (literally)
264545245234523523523232323

Dunno if you guys want one or not :smiley:

Also, the reason for the shiny picture is because I tried printed on the backside of my print bed… been having adhesion issues again, made it extra shiny XD



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Dang, need more heart icons

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XD :green_heart: :green_heart: :green_heart: :green_heart: :green_heart: :green_heart:

How about that?

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Guess Look what made it in today ;D

EDIT:
Did a dry fit, literally everything fits! :partying_face:


EDIT again… saves posting XD
Built my rack today. May I present “Wanda”, the Kosmo format rack ;D



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Lowes had run out of lumber at the one I went to, so I couldn’t get the last of the wood until today, but here’s the rack I built (planning on painting after christmas)

So Wanda is now ready for make-up and Kosmo modules ;D

:smiley:
Ahhhhhhhhhhhhhhhhhhhhhhhhhhh!!!






does a massive happy dance

Took 6 hours 15 minutes over a livestream XD

EDIT 3:
Mounted the panel today, was worn out yesterday from building it. Still waiting on FC supply, but otherwise it should be fully functional as the prototype worked great and they are the same schematic file, so should be okay… But I’m immensely curious how it’s going to sound when things start getting inter-patched ;D

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