There’s no reason those couldn’t be translated to CV. Modwheel would be great for an LFO or an effect (like phase or reverb wet/dry) and aftertouch would be a good filter cutoff or resonance, or sustain level control.
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Or this:
which has 12 CV’s and 6 gates and is really cheap. It has one draw back, it produces positive voltages only. But by adding 3 lm 324’s I was able to change that. Now I can choose using a as switch between 0 - 10 volts and -5 to 5 volts.
An alternative would be the midi2cv interface by Pete Kvitec:
which has 4 midi 2 cv ports and 4 gates. This has a lot of extra functions. It can e.g. switch cv-outputs to function as an independent lfo producing voltages that oscillate in various shapes.
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Sam says he’s working on a Kosmo packaging of CV-12:
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indeed!!! but yeas it is 0-10v. as everything I have worked with from day 1 was positive voltages I have only done positive. as I found -5 to 5 a bit. of a neusance as when the oscillators for instance are unplugged they go all high pitched. so personally for my Kosmo 0-10v is suffice :).
this is an incomplete prototype I’m working on it atm. I suspect if all goes to plan itll be the next one up! after the VCA’s which. are hopefully up today! 
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just a heads up! check the midimuso site for all of the different modes, it means the module in. the above post I just put up. will be. able in some modes to do what. your after if you make them midi! )
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The circuitry I added to the CV-12 consists of a LT10021N which acts as a 5 Volt reference and 3 quad opamps (LM324) which subtrack 5 V from the CV outputs therefore giving those the output range -5 to +5 V. A switch is included which bypasses the LT1021N and effectively makes the opamps subtract 0 volts from the original CV voltage range thus preserving the original voltage range. So the switch makes it possible to choose between -5 V to 5 V or 0 - 10 V. The CV-12 doesn’t use a DAC but uses PWM to load a capacitor to a certain voltage. Changing the duty cycle of the pwm changes the voltage. The capacitor however looses its voltage after a while, so the pwm must be applied continuously until you want the voltage over the capacitor to change. Note, that sometimes if you send midi data to the CV-12 in order to make a voltage rise slowly or fall slowly you may be able to see a ripple in the output voltage of the circuit. If your application is not critical in that sense then de pwm method results in a much cheaper circuit. To get 12 CV outputs using DACs is much more expensive and the circuitry will be more complex.
Note: I added 3 lm324 opamps to the circuit to do the subtract trick. This requires that the circuit also has a negative voltage, which the original circuit does not need (as it only produces voltages between 0 and 12 V). In stead of adding 3 lm324 to the circuit one could use the 3 lm324 opamps that are already in the CV-12 that buffer the capacitor voltages and change them into adders. This would require a change of the PCB. I’ve send an email to the CV-12 builders and they were very interested in the design change proposal. Whether they are going to incorporate this in their design, I do not know.
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What’s the use for negative CV? (generating audio via raw MIDI seems a bit impractical and the CV-12 output filter has a cutoff frequency of ~160 Hz anyway)
My present Eurorack setup’s built around a Moog Mother-32, which uses -5 to 5 V CV generally — the EG is positive only and the VCA takes a positive CV when in EG mode but otherwise it’s ±5V. I believe similar things are true of all the modules I have. I’m surprised to hear Sam is doing otherwise. Seems like that’s going to make interfacing with Eurorack modules, or Eurorack-derived Kosmo modules, harder and more confusing, isn’t it? Not that you can’t build level shifters, but …
http://musicfromouterspace.com/index.php?MAINTAB=SYNTHDIY&PROJARG=HOT_TIPS/dc_level_shifter.html&CATPARTNO=&PN=1&SONGID=NONE
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Having trouble understanding this. On the Mother-32 the oscillator is around middle C or so when input CV is zero volts. (Well, depends on what the internal button “keyboard” is doing but my understanding is that runs -5 to +5V.) And the Befaco has an octave switch so it can be in any octave when no external CV is applied. Maybe middle C is what you mean by “high pitched”? But if it changes when you plug CV in it just implies the CV is negative, right?
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Ah, forgot about non-euro/kosmo stuff 
I’ve been following “eurosynth” levels for my homebrewn “kosmo compatible” stuff, which is 0-5 V for CV/gate/triggers, but I see Doepfer uses ±2.5 V (5 Vpp) for LFO output, while envelopes are 0-8 V.
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Mother 32 is kind of in its own realm. The 1v/octave standard doesn’t have starting or stopping points incorporated, so here’s a handy partial guide to some of the most popular modular and semi-modular equipment:
https://learningmodular.com/matching-octaves-in-your-modular/
You may not need it, but it’s nice to have as a reference in case you want to confirm what your experience is telling you.
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Bizarre, that document says
To try and maintain some level of compatibility with existing EuroRack systems, the
EuroSynth specifications have been designed using the Doepfer A-100 system and in
general, a EuroRack components and EuroSynth components can be interchanged with
minimal or no changes.
and then goes ahead and says use banana jacks and positive-only CVs. Neither of which I can find on a Doepfer.
Frankly positive-only CVs make my head hurt. Negative CV means “go down”. If you have an oscillator outputing middle C and you want to add an LFO CV to modulate it up and down from that, it makes sense to me that that CV should be centered around zero. If your LFO is 0 to 10V then it won’t modulate the oscillator around the pitch it’s already at, it’ll only sent it to higher pitches. VCAs normally can’t go through zero so it makes sense for envelope generators to be positive only. At least to me it does.
Not really — look at your link under " Eurorack VCOs". There are several others that have 0.0V for C4, and even the rest that use positive voltage for C4 generally have a range that implies they’ll respond to negative CV.
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hey basically I have gone off the beat step pro and also the Kenton, where 0v is C-2. so I’ve just been going with that this whole time. so I just keep it all in the plus.
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im wondering what the advantages of it being -5v-5v would be. for the sake of simplicity of the circuit I’m going to keep the midimuso module in the plusses. but I’m just interested how it works with other people!
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also sorry I very much oversimplified my answer. yes when I saiid high pitched. its just because the voltage is in the minus. and you pull the jack out and it pops back up to middle C. however for me, it just makes more sense to keep it in the +. and use an octave switch. hence why I didn’t bother with the module in the pic for my touring synth
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Yeah, it’s mostly someone’s opinion, not a widely accepted industry standard, but I found some of the definitions there useful for my own work.
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Oh shit Sams already on it—I gotta have the kosmo version!
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A -5V to +5V range as CV-input range makes it possible to also use any audio signal as a control voltage. A module that is built to accept -5V to 5 V on its CV inputs implements this in a straight forward way. Given an input range of 0 - 10 V would imply that one would need to add 5 V to the audio signal to be able to use that as a control voltage -> one would need extra hardware for this.
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