Hi, I have taken the decision to build my own synth, based on the Kosmo design. It’s a long time since l have held a soldering iron, so it will be a slow build. I have taken a costing on a bom and the first few modules will be expensive, but the cost should come down as l build up my own stock of parts. Should my first module be a Midi to CV, as l want to play the synth via my keyboard? Any and all advice is welcome.
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if you have already made a power supply + 12 / -12 and the case, the first module in my opinion is a VCO (Sam’s CEM3340 for example). There is a some simple version on stripboard or the “Performance” one on PCB
Stripboard :
PCB :
for me the oscillator is the heart of the modular, the basic sound, and after you add some module to transform, modify … it
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Thanks, parts for the power supply are on order, l have yet to build the case as l want to incorporate the keyboard into it. I will take a look at the module that you recommend.
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I second the VCO, but you may also consider the performance filter if you already have sound sources to put through it.
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Christian, thank you for your recommendation, I’m thinking of building a module per month.
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It’s nice to have a case, but I’ve built four Kosmo modules now and still don’t have a case to mount them in! I’ve been holding off because I don’t want to go wood shopping until the pandemic new case rates drop significantly in my area, but that looks like it’s going to take longer than I thought. I might have to bang something together out of the materials I have as a stopgap.
Anyway, you can at least test modules without a case, just not very easy trying to actually use them.
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which country are you in?
vco after the psu but the
LMNC pcb one is not the simplest 1st module
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Does the performance filter self-oscillate? If so I could see making the same argument for it as the oscillator, or at least putting it on the same footing for the same reason. But the oscillator is probably always going to be the most fundamental conceptual unit.
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I was thinking of building a case with the keyboard as part of it, but on reflection it may be better if the keyboard was a separate unit.
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I’m from Liverpool, England.
I have just seen Sam’s video on building the CEM 3340 VCO, just before the end he shows a module with three vco’s in the one. I have just become a Patreon of Sam’s, and I’m hoping to find further information on this.
It’s a lot to learn.
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Welcome!
The three oscillator/two filter panel in this video is 3× Simple 1V/Oct Oscillator and 2× Simple analog Low Pass Filter (with one configured as a high-pass filter) behind a single panel.
Sam’s since then made performance versions, with panels and PCBs available for purchase: #1222 Performance VCO and #1113 Performance Filter.
There are build threads here about all of them.
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I could send down one each of these red pcb+panel @cost. They are absolut bottom of the technical scale (almost)
the one with one button is a very basic CEM3340 VCO based on sams sketch on the website. it’s not a difficult build at all just a few mins work… there is an error on the PCB but easily resolved. it outputs tri and saw and has CV in.
the second is a 3ch mixer, this is even more basic to build.
those together get you basic waveforms with some amplitude control. fairly easy to trouble shoot.
Apart from the CEM and the Alpha Pots. Everything else is cheap…
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Fredrick, thanks for the information on the two panels, l will order them from the store, but l will still build the single vco first.
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A PCB version of the simple CEM3340 VCO would indeed be a very good starting module.
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Twinturbo, please forgive me, are you saying that you have panel for sale? If you are then l could be interested, many thanks.
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Yeah,
simple VCO,
3 ch mixer
And have some of analog outputs Microcosmo.
You may not end up using them for long but good for test rigs and cheap enough not to worry about damaging.
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Yes l would be interested, l will pm you, thanks.
this is the link to AO’s module for you. There’s a number of others who have this module. I am building it finally over the weekend.
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On their way down the M6 to you 
Rob
Many thanks Rob, I’m looking forward to start this project, l have started to order components and other parts.
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