Pitch Range of MIDI 1U? (-5V to 5V vs. 0V to 10V)

Greetings. I noticed that the new MIDI 1U has a pitch range of -5V (C-2) to 5V (C8), whereas the prior uMIDI 1U had a 0 to 10V pitch range for the same range of notes.

I use a few digital oscillators that don’t recognize negative voltages for pitch, so I’ve standardized on C0 at 0V. This means I would only get a five-octave range with these VCOs when using the new MIDI 1U, whereas the original uMIDI 1U had a much greater range.

I don’t see a way to change this voltage range with the config app. Am I overlooking something? If not, would it be possible for a future version of the app be able to change this parameter? Ideally the new module would be backwards-compatible with the original one.

Ah, I think I just answered my own question: I just read the manual’s description of the “Coarse Tuning” parameter. This seems promising.

Danjel posted here that the new module can only do bipolar voltage for pitch.

I have a similar dilema to you.
My one source that is a major annoyance is Piston Honda MkIII. It can only do 0-8V for pitch.
I do prefer Bipolar pitch because it is much easier to tune unpatched VCOs to C3. Even Mordax DATA can’t tune to C0.
The workaround, as you suggest, is to adjust the tuning on MIDI 1U so that 0V is at the lowest MIDI pitch possible - then at least you can get 5 octaves out of unipolar digital modules.

I kept my µMIDI 1U, so it is now dedicated to Piston Honda. Everything else in my system works “properly” with bipolar pitch.

You could use something like the Doepfer A-185-2 Precision Added to add 5V (or for the Piston Honda, 3V) to everything coming out of the 1U MIDI.


The “Coarse Tuning” parameter seemed like a reasonable workaround, but I was hoping for something that would truly solve the problem, and it looks like it’s not going to happen.

That said, in my personal situation it’s not that big of a deal. I’m primarily using a Linnstrument, which only has a five-octave range, and it can easily transpose by octave for when I need to go higher. By default, the way the notes are laid out makes me lose a few semitones on either end, so I’ll give this some thought for how to address it.

Sure, but I’m so weary of having to dedicate a new module to the purpose of overcoming the limitations of an existing module. I’d much rather have a module that functions as I want it to. And as mentioned above, I can certainly make do with the bipolar range in this specific case, so it’s not a deal-breaker here.

Trying to decide on a voltage range for CV outputs on modules like this is always a dilemma. There’s a tradeoff between a larger range, higher precision, or more complex circuitry / calibration.

@studioutopia is correct, after our experience with the µMIDI we found that it’s generally easier to tune VCOs to a mid-range pitch at 0V and then be able to go in either direction from the MIDI module which is why we went with -5 to 5. It also allows us to have bipolar CC outputs and that sort of thing.

For oscillators that can’t take pitch input below 0V it’s probably best to just decide what note range you’re going to be using it in and then tune to the lowest note of that, or an octave below. You’ll still get 5 octaves which should be plenty for most musical applications, that’s more than most real-world monophonic instruments. It just means you might have to re-tune the oscillator if you’re switching between using it for say bass and melodies.

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