Granular processing

A couple of days ago I plugged my guitar into my modular synth rack, something which, curiously, I hadn't really done before. I set up a very simple patch centered around the famous Mutable Instruments Clouds module, with just a couple of parameters modulated by noise to randomize them, as a quick demo for a scenario someone on Facebook had asked about.

Clouds is a granular processor: the audio going through it is chopped into little samples or grains that are played back in real time with varying density, size (length), shape (hard, slow or smeared attack), stereo field position and pitch. At high densities, this results in a thick "swarm" of overlapping grains. With more low-key settings, it can also be used as a kind of delay; the position of the "play head" (the distance in time to the live played audio) can be set or modulated to change the delay time.

[Blocked Image: https://mutable-instruments.net/modules/clouds/images/front.jpg]

In my recording, size and length are randomized by patching a noise source into their respective CV inputs. Pitch is also randomized, but with noise quantized to the notes in a minor 7th chord for a more musical result.

At the end of the recording, I stop playing and "freeze" the audio buffer, so that the last few seconds captured are retained and used to generate the grains instead of the live audio going through. I then use the position knob to scrub through the buffer.

Now. Is this something I miss in the Kemper? Nah, of course not. It's not an effect I expect from a guitar amp, and I have my modular set up right next to my Kemper so I can use it anytime I want.

But! I can't help thinking how cool it could be. Imagine linking the playhead position to an expression pedal to scrub through a frozen buffer like I do in the final half minute. Or simultaneously morphing grain density and the depth of random size, texture and pitch variations, to transform a simple sustained note into a mad stereo swarm...

What's more, I think the algorithms used for the Kemper's crystal delay, smeared delay, pitch shifter, pitch shifted delay (which could probably be used for something similar to my demo) and delay hold are already pretty close to granular processing anyway. The difference, I think, is that in those cases, the grains are carefully lined up to overlap as smoothly as possible, while the "granular" effect is created by making them more chaotic and fragmented.

Hm, yes. I hadn't even thought of that but you're probably right.

Clouds is a hardware Eurorack module, by the way, not a plugin (although an authorized port now exists in the free "virtual" Eurorack emulator VCV Rack). But of course it's still software, running highly optimized on a dedicated chip that it doesn't need to share with anything else.

I guess my Kemper and my modular synth will just have to become very, very good friends.

Quote from Monkey_Man

EDIT:
I see there's a picture of the Clouds module in your OP; it didn't come up when I first read the post. I don't know if you've added it since but at any rate, had it loaded the first time, I'd have known that you were talking about hardware.

Sorry Nicky, I sneakily added it shortly after posting, as I was touching up the wording here and there. I can't help it, I'm a compulsive post-posting post editor. I do have Granite in my VST folder, but since getting into modular hardware I haven't used it that much.

The Clouds module has been discontinued for a while, and as usual with Mutual Instruments, the whole thing -- software and hardware -- has been open sourced after the initial factory-built batches were produced. A lot of people are making DIY versions now, and custom firmwares have been developed (as well as the virtual VCV Rack port). Mutable Instruments is a one-person operation; Olivier Gillet is an absolutely wonderful maker; his generous personality, as well as his strong, well-considered feelings on usability and hands-on, inspiring interfaces, are evident in everything he makes. I love the sense that a tool or instrument is the product of a singular vision, like our beloved Kemper, of course!

Quote from Monkey_Man

Seeing as you have Granite, why not fire it up and check the CPU usage for interest's sake? Bear in mind also that when I mentioned the 2->3GHz thing I meant to state that there'd likely be at least 4 cores involved.

I'm running my DAW on an industrial workstation with two 8-core Xeon-processors (long story ), so in my case I'm afraid it would be even less representative of the proportional CPU usage on the Kemper, which I do believe would be considerable. And disabling the profile section or indeed any other effect to make room is not an option, of course!

Quote from Wheresthedug

Woah!! I’ve no idea what I just heard there .......... but I like it

Hehe, thanks! It's like running the sound coming from your guitar through a shredder, with little chips flying off in all directions. What I've done here is actually a pretty mild form of the effect -- it can also sound very buzzy, pretty much like a real shredder, if the chips are set to be shorter and even more random. But used with restraint, it can form a very nice, almost impressionistic cloud of ambient chords...

I had a feeling from your Soundcloud that you were a fellow traveller down this particular rabbithole, @DonPetersen.

And yes, that warning is very apt. VCV Rack came out some time after my first steps in "real" modular, but I've recently used it to try out a couple of MI modules (Marbles and Plaits), after which I immediately ordered them for my rack. Very dangerous.