Polyphonic effects

Plugins & Modules
1

Is there any way to add reverb, delay or any other effects to polyphonic channels without using too much space?

2

From the look of this:

it appears that only the Surge reverbs are polyphonic, and a similar search using the Delay tag can help to more easily spot the polyphonic delays.

1 Like
3

Do you mean you want independent effects for each polyphony channel, or just apply the same effect to the summed (aka mixed) polyphony?

If an effect module doesn’t sum/mix up the polyphony channels at its input, it is not following the VCV guidelines, and it should be reported to the module developer.

edit : Interestingly enough, for example the VCV Fundamental Delay module does not do that summing! This can be worked around by routing the polyphonic signal into the Fundamental Sum module and from that’s output into the effect’s input.

1 Like
4

Is there any benefit for using a polyphonic delay/reverb that has only 1 type of setting for all the channels, instead of using 1 stereo send on a mixer?

4 Likes
5

Thanks for the help!

6

benefit for Intel - it will use a lot more CPU for the same sound.

6 Likes
7

Yeah! Hard to think of one for the typical use case for reverb (as space): putting sounds in space(s) at the mixing stage. For that kind of use poly modulation would be better applied at the mixing + summing into send bus stage than on the reverb itself.

@param260507 for the reverb as space use case where you want to do advanced modulation on each channel beyond what a mixer can do, VCV soundstage is arguably more like what multi channel reverb should look like than a ‘poly’ reverb module.

I guess there’s weirder uses cases like setting up the reverb more like a resonator stage in a synthesis signal path. The rare poly reverbs we have - like surge - are worth a look for that. So is using stoermelder MIRROR with your preferred reverb modules.

8

Afaik it actually wouldn’t be quite the same sound, but not necessarily in a desirable way depending on the use case. (Like sending stereo signals through a pair of identical mono reverbs vs using a true stereo reverb.)

9

Just remembered that there is a polyphonic delay from Stocaudio:

I’ve only really used it to make flangers manually but you could do more than that.

edit to add that Rackwindows has some poly effects but not there reverb. They have a weird reverbish thing called Distance that’s poly but I don’t think that’s a reverb as such.

10

Hmmm. From the Surge Manual page: “The FX handle polyphony by summing a polyphonic input automatically.”

So, it’s really only half-polyphonic? There should be another tag invented for this sort of behaviour. As it is, I can’t find an reverb module that outputs a polyphonic signal.

11

“back in the day” it was very common for a reverb to sum both inputs and generate discrete L and R outputs.

12

There’s massive benefit once you move beyond stereo. In quad you could use a single delay line for a four-channel poly cable, then split it to each of the four speakers, preserving quad-pan info, etc., instead of running four identical delay lines, one for each speaker.

13

From the plugins I have the following reverbs claim to be polyphonic:

  • Plateau
  • Super Echo
  • The Surge XT ones
  • Sapphire’s Tube Unit
14

(Post edited for formatting)

The Surge effects are definitely polyphonic, but you have to right click and enable it in the menu. Airwindows is also poly, and has some great reverbs.

I don’t think there’s much benefit using polyphony for mix bus effects, but I use poly effects a lot in a different way. I take a mono signal (usually live guitar) and duplicate it onto 16 channels with a mult. Then I send the effect poly modulation, so that each channel is getting a different LFO for example. You can think of it like 16 delay pedals in parallel, where each one is the same pedal but has someone twiddling all the knobs in a different way on every one. This works really well with modulation effects and filters too, I think it sounds epic. Not sure anyone agrees with me though! Some good modules to try this with are:

  • Vult Rescombe
  • Instant Delay (premium but nuts)
  • XFX filter
  • Surge XT freq shifter / phaser / flanger
  • Airwindows (delays and a few other effects)
  • Polydelay
  • Surge XT Nimbus (Clouds clone)
3 Likes
15

Replying here because I’d gotten it into my head that a “Polyphonic” tag meant that the module can not only accept poly input, but can also produce poly output
 as I discovered to my chagrin, Plateau, for instance, does not have poly out, only poly in.

1 Like
16

Yep, I would argue that’s tagged incorrectly; ‘Polyphonic’ modules should definitely produce polyphonic output.

Try Airwindows and use the Galactic reverb, that’s properly polyphonic. That may sound like it doesn’t make much sense, but I used it once on a poly arpeggio so that each note was getting a differently modulated reverb. Basically, this just made it sound more interesting than a regular stereo reverb.

1 Like
17

It seems that Andrew would disagree:

And I do as well. I think polyphonic should just imply the ability to work with polyphonic signals, in some capacity, be it at some/all inputs or some/all outputs.

2 Likes
18

I disagree as well.

Some modules (such as Sanguine Monsters’ Oracle) take a polyphonic signal and produce a monophonic output or take a mono signal and produce a poly out.

2 Likes
19

It seems that ‘polyphonic’ can mean a number of different things indeed, even though at least in the VCV Rack manual it reads:

If your module supports polyphonic inputs or has polyphonic outputs, then it can be considered a “polyphonic module”, so add the “Polyphonic” tag to the module’s manifest.

To me, this definition may work for developers, but I find it less useful in practical terms for a user.

Therefore, I would also like to open the following thought for discussion:

One major differentiation I find helpful in praxi is by the type of signal that is being processed polyphonically, i.e. whether it is 1.) Control Voltage (CV) signals or 2.) Audio signals. The latter I would call ‘(audio) effect’ modules.

I am aware that current definitions don’t really specify this distinction, possible because in the end, everything merges into being ‘Voltage’ anyway.

Moreover, the issue is complicated by the dilemma that module tags sometimes appear to be rather arbitrary as they do not seem to be curated rigorously.

The taxonomy used in the ‘Utilities for polyphonic channels’ list attempts a more practical approach. There still are inconsistencies in there, too, but it is at least an attempt to give the term ‘polyphonic’ a bit more granularity from the perspective of the user. Hence the view there is more for practical purposes, from ‘what do I want to achieve’ to ‘which module can I use for that’.

1 Like
20

Yeah, the quote from the manual seems pretty clear (input or output). Also I think your distinction between CV and audio is not helpful, since one of the powers of modular is “everything is a signal”, which you admit to as much in your following paragraph.

I would agree with helping the user along a bit more. We do have the thick poly cables, but I have decided for myself, that if I ever get around to developing modules, then poly inputs will be marked with a few, small, ingoing triangles at the top-left rim of the port, and poly outputs with outgoing triangles at the bottom-right of the port. In that way there’s a clear sign of which ports accept or deliver poly signals, akin to the recommendation to have the background of output ports be in reverse color, which I agree with and think it’s a shame that not everyone follows. I think that would really help users.

2 Likes