DIY midi to cv module based on Midimuso CV12 kit

Surely! Hope it won't take much time for the items to be delivered. Seems that CV12 module is a near-zero investment project.

I’ve assembled the kit, though I can’t get any cv out of it. Seems like I’ve fried the traces or components on the breadboard. I need to show it to a friend of mine who is assembling his own preamps, hope he can fix it. 

For the 10 to 5V scaling a simple voltage divider should work with two resistors. It’s the same as using a linear potentiometer at the half-way setting which is often done on modular synths to attenuate signals.

To halve a signal level you need two resistors of the same values, like two 50k Ohm resistors.

www.allaboutcircuits.com/tools/voltage-divider-calculator/

You shouldn’t use this to regulate a power supply down, but for CV it shouldn’t be a problem.

Wait for your experience with CV-12! I'll try to check mine more thoroughly with multimeter when I have more time. In case of no success I think I'll just order another one, they are not too expensive. Yes, if you have doubts or haven't come across similar projects, I'd advise you turn ask a skilled person for help.

Yes, careck, thanks, I'll check this once I get mine working)

ok I hadn't looked at the specs.. I was commenting on what was being said....  ( and generally you dont want to start scaling pitch voltages) 

but of course, we should all turn to the specs  

so all outputs on the CV12 are 5v ! , so will work as is (page 2) 

what should be noted in particular is page 1...


so for AE modular you would simply not use 10v auxiliary kit (this would only be needed for Eurorack) , then you will only have 0..5v , set a v/oct all will be good

note: I dont know what OP has bought as a kit precisely, I'm just going off the CV12 manual

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on a more general point, having read some of the above comments on this post

before connecting anything to the AE modular directly always check with a voltmeter/multimeter first, don't rely on spec , what you're expecting, and make sure that you are getting the full voltage range  (e.g. in this scenario, you need to be sending midi CC 127, note 127) its quick and simple, and even if its ok - it'll help verify your understanding is correct - and it'll stop you potentially damaging you AE modular.
if you want to be really safe then use a diode clamp - or use a CV IO module, or the the nanobridge which has this protection built in it.


 DIY with the AE modular is simple, but you still have to do some 'due diligence' before connecting stuff to the AE modular patch points as you have to assume they are unprotected.

yeah, the master/4io are clipping the inputs, Id assume a clamp - but never looked  

but if you look at the picture of the nanobridge , you can clearly see the two diodes and resistor, per input ... (so its exactly the circuit as pictured above) 
though they also have an 'unprotected' input... which they seem to imply is used to bypass this, this is used for the output (as you dont need to protect outputs) 
but the interesting note is they say also for v/oct input - which makes me wonder if the diode clamp can potentially skew the voltage slightly (which you'd not want for pitch input) 
unfortunately, I dont have one to test... so am just going from the description  

Ive been meaning to order a nanobridge, as whilst its a simple piece of kit its really great value at 31 euro for 14 IO !
(I think robert should make one for those of us wanting more CV IO, that can be out of the case) 

are you sure?


I don't have a CV12 so cannot say...

but it already does 5v on all outputs, so it doesn't need amplification to supply 0..5v for pitch (only above 5v),
so its purely software, to allow v/oct to 5v... not hardware , and I cannot see why they would not support its




but I admit the calibration section reads a little 'odd', 


this seems ti  imply if you set to v/oct, its actually going to put out 0.5v/oct 

what Id have expected, is if you use a 2x gain, then when you want v/oct you set it to 0.5v/oct (which it does support) 
this would mean you can get v/oct with and without the 2x gain circuit. at least that is how I would design it
... so perhaps just the user manual being a little vague?  (its not the best manual/spec ive read ) 


anyway... one of those things to try out if you have the board, Id personally want to avoid a gain circuit if possible, as it means the pitch output become 'special' compared to other outputs which is a bit of a shame really.


( indeed as you say, if you do need the 2x gain, you can just feed it 5v , then the opamp will be limited to 0..5v. d want to use a rail to rail opamp to make sure you get a decent range on the pitch) 

Thanks, humpink! The user manual is sort of vague, really. However, the thing doesn't work yet. I checked it for continuity with multimeter, everything is ok, no shortcuts either. It does output voltage circa 4v which does not respond to incoming midi. And the IC2 (LM317) gets very hot, so I switched the power off immediately. Waiting for the Midimuso to answer my letter.

Octex 

So, just saw on a facebook synth diy page that the same guy is soon to be (re?)releasing pre made kits with the CV 12 already put into the 4cv/4gate mode. Seems to be an easy way to get four lanes of V/O from a midi source you're not into the whole soldering and troubleshooting part of the dealio.