Splitting CV/Expression in2 manymany

[manymanyhaha]

I bought a Squarp Pyramid and Koma KH301, bought both for real cheap, will keep one for this purpose after experimentation.

Basically, have lots of pedals with expression and/or CV inputs and since Mobius generates midi clock, thought it would be fun to experiment with generating CV/Expression from midi clock using either the Pyramid or KH301 and voila . . . . art? chaos? both? neither? may as well put a contact mic in a toilet bowl? I would like to find out!

But, each only has one or two CV/Expression Outputs.

Anyone have thoughts about compact methods to split a CV/Expression signal into several/many CV/Expression inputs?

Non-modular (so-far)

[Schlatte]

Well, there is always the Copilot Broadband: https://www.copilotfx.com/broadband.html

If you're a DIY guy, you can check out my expression multiplexer: viewtopic.php?f=286&t=63850#p1386170 /shameless self advertising

[qersty]

https://missionengineering.com/shop-2/p ... ssionator/

[Schlatte]

Ahhh yes, almost forgot about the espressomaker!

[manymanyhaha]

I do a fair amount of DIY stuff which is why I'm trying to avoid it for this: Too much to do.

But your Multiplexer looks really amazing, as does the Broadband and Espressomaker

But I'm looking for more outputs. Do CV/Expression signals travel like normal audio signals and thus, can be split with the same splitters that audio signals use?

[lordgalvar]

With expression inputs, you'd basically have to create an array of pots to keep the circuits separate. CV can multiply and mix and stuff.

Some CV is bipolar (AC), some are unipolar (DC). It will depend on the circuit. You can rectify an AC signal or just block the negative portion to create a DC signal. Most pedals I see are 0-5v DC. Moog and some others can handle AC. For the most part, you can use passive and buffered multiples and attenuators.

Expression inputs are basically just pots broken out of the case. They become part of the signal and can't really be mixed with another pedal (you're basically crossing two circuits together though one pot). It's just a variable resistance (or voltage divider) being replaced in the circuit. I would think the easiest way to go about multiplying an expression signal would be with digital pots (more exact because you can match the correct value of pot for the circuit) or by controlling the voltage to a vactrol or ldr/led setup (which is more variable and may have the wrong resistance and/or taper....but easier to whip up with out a computer).

Some can handle either. Depends totally on the pedal.

https://www.instructables.com/Digital-P ... d-Arduino/
https://aisynthesis.com/ai001-multiple-build-guide/

Pyramid, iirc is 0-5v on CV outs. KH301 is like 0-7v on the envelope and I don't remember on the LFO. Those could all be passive multiple'd no problem, but I don't know what the inputs of your other pedals are (Lastgasp, for example, are EXP but listed as CV).

A mixer and passive attenuator would be good simple things to add (like mixing the LFO with the envelope). The attenuator would be useful if a pedal accepts like 0-3v (I think some of the Moog were like that).

[Schlatte]

I do a fair amount of DIY stuff which is why I'm trying to avoid it for this: Too much to do.

But your Multiplexer looks really amazing, as does the Broadband and Espressomaker

But I'm looking for more outputs. Do CV/Expression signals travel like normal audio signals and thus, can be split with the same splitters that audio signals use?

How many outputs would you want? With some slight adaptations, the Expression Multiplexer could also do 6 or 8 channels.
If you only need CV stuff it would be possible to do it all analog, but if you also want to satisfy EXP pedals, you'll have to use digital potentiometers.

[manymanyhaha]

From your very helpful explanations, lordgalvar and Schlatte, I'm now understanding why I was having a hard time finding information through google searches: It's a bit more complicated than I was anticipating. Per usual

Currently I have 10 pedals on my board that have Expression (5 of them), CV (1) or Exp/CV (4) inputs. But I am always pulling stuff off the board and replacing with other stuff so versatility is really where I would like to go.

But, since these pedals and all pedals heavily orient towards expression inputs, that should be where this project focuses. So essentially I'd need to convert the CV from the Pyramid or KH301 to expression and then split that. Ooof...

[Schlatte]

Well, 10 outputs is a lot, but entirely doable. Depending on what kind of controls you would like to have on such a device (simple "dumb" splitter, that just mirrors the input signal or more sophisiticated device with different taper settings or inverted sweeps, etc.) it also shouldn't be too big or complicated. We can also talk per PM if you would want to pursue such a thing