I have just added µMIDI to my cases to work alongside my Expert Sleepers FH-2. I am used to the FH-2 pushing a bipolar pitch signal (-5V to 5V), which allows all of my oscillators to be at C3 when their tune knobs are pointing at noon - Except for one - the Instruo Cs-L upper VCO. The tuning on this saw-core VCO puts C3 at 9 o’clock.
The µMIDI puts out 0-10V unipolar, which means that without using two channels of the Quadratt, I am unable to go as low as C3 on this VCO.
Can an option on µMIDI be put in the firmware and configuration utility to enable bipolar pitch CV, so 0V is C3?
- or is the hardware limited to only output unipolar signals?
Hardware limitations is most likely.
I don’t know anything that uses unipolar output that can be converted to bipolar from what I’ve read. This topic comes up a lot with different modules and the answer is always the same.
The hardware can only do unipolar voltages. So you need to set the tuning of your oscillator lower or else sum with a negative offset.
Any way you can make a 4HP 1U module with two jacks in it (in and out) with the output = (input - 5V)?
Actually - I could use a bunch of those for Xaoc Zadar, Mutable Stages, Pamela’s new workout…
Are you playing C3 out of your MIDI sequencer or DAW or whatever? You can always just transpose down a few octaves in MIDI to get a lower voltage out.
The FH-2 can be reconfigured to output 0-10V.
Thanks @kamil. The solution is to transpose in the µMIDI control panel. That way MIDI notes coming out of the DAW are at the same pitch for VST’s, MIDI synths, and Eurorack gear via the µMIDI without transposition.
@RadicalQuiver - yes, this is easy. The FH-2 can use 0-10V. The problem is that all of the oscillators I have (Instruo Cs-L, Ts-L, Mutable Plaits, and Pittsburgh Primary), and nearly all I’ve tried out there are designed around a bipolar pitch CV input - Including Rubicon and Dixie with C3 or C4 at 0V. Most oscillators are designed to get C3 or C4 with the pitch knobs pointing at noon. Except for the upper VCO on the Instruo Cs-L, which uses 9:00 as C3, to allow for extension into really high ranges as a modulator - just like the Verbos CO.
Just found this…This article answers a lot (including Kamil’s statement!!) -
I’ll work with this knowledge! Thanks Chris - @LearningModular!!!
One point to make -
If the Eurorack community standardized on bipolar -5 to 5V as the standard for pitch CV - there is one major benefit: When you unpatch an oscillator, there is 0V to it’s pitch. You can just tune it to C3. All neat and tidy. You can tune it even if other things are going on.
If you try and tune an unpatched oscillator (0V to pitch) to C0 (17.32Hz) or C1 (32.70Hz), most tuners - including my Mordax DATA (which bottoms out at 27.50Hz) will not register, or will be difficult to stabilize. A 3V or 5V voltage source is required, or you need to stop everything, and send 3V+ from your MIDI-CV converter to it, which breaks your workflow.
There is no user benefit to using 0-10V for pitch CV, as far as I can tell.