Opinion: multiple CVs to modulate single parameter?


Is it a nonsense (or not) to modulate a specific parameter by multiple CV sources?

My new clocking module (in development) have 8 CV inputs. Technically it’s possible to modulate internal parameter (such waveform morph, voltage amplitude, voltage offset, phase shift) via many CVs (combined), but is it useful or totally useless/unrealistic (aka one CV only is enought)?

Thanks in advance for your advice.

I think it depends on the scenario. E.g. the two V/Oct inputs on EvenVCO are quite useful.

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Surge XT has this feature with 4 CV signals that can be mapped to any parameter simultaneously. So I would say it’s very useful.


I have used two before for sure. Overall larger pitch variation from one note to another, and smaller adjustments at the same time. So a slide with vibrato basically.


Thanks Lars, @Ahornberg & Paul! :ok_hand:

I’ll consider this option, BTW!

The module I mentioned above: :wink: by default CV3 upto CV8 are “native” CVs (CLK and RUN input may become respectively CV1 and CV2. Also, native CV3 input may become RESET input).


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@Ohmer : Are you talking about multiple inputs for the same parameter? In which case an external 8-channel CV mixer would do the job. Or make it an expansion module to be parked on the lefts side.


Yes, John, one or multiple inputs can (optionnaly) modulate the same parameter. This parameter is - de facto - fixed by a fader (fixed base value), but can be modulated “around fixed” by one CV (or many). Hope my explanation is understandable.

You’re right about a CV mixer (many CVs mixed => out goes to one CV input of my module), probably better for CPU / ressources save. Similary, CV amount may be handled by a VCA (or attenuator), inserted before CV input, this does the job! A contrario, the cons are more modules & cables in the rack…

if you particularly like the surge style mixer mode, we also have a pure-play cv mixer which is a 4 in 8 out module which lets you do depth assignment to each of the output cvs and then send it out a port.

that, in theory, allows a module with a no-attenuator single cv act as if it has a surge mod matrix, at the cost of extra wires and modules of course.

I personally use multiple modulation sources on single parameters all the time in my sound design, both in rack, in vst synths and in daws which support it. its one of the (two) factors which motivated the surge mod matrix design (the other was avoiding N CV inputs for N parameters)


Thanks Paul for your explanation, it’s very interesting! of course any solution have their pros and cons.

EDIT/ADD: I’ve tested to support all 8 CV inputs, but the CPU usage becomes too important in my opinion (by using all 8 CVs to modulate all possible parameters, it was the extreme scenario) - but not of all parameters are implemented at the moment in my module - such pre-offset before quantize and euclidean parameters (steps, pulses, offset, pads), so I consider it’s more reasonable to modulate any parameter by only one CV source, not more.

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