Hands on: Cong Burn’s Stacks plug-in and iOS app synths, loops, and layers

From the creator of Strokes, Stacks is a unique 4-voice wavetable morphing polysynth combined with a 4-track granular looper. But that description doesn’t really do it justice: modeling and digital grunge combine to make a raunchy instrument that behaves like an experimental studio.

I’ve been working with a test build of Stacks in its desktop version. Once you get into it, this thing oozes personality. I’ll be honest; I never got fully immersed in Strokes. And this is not an affair you want to use without the manual. But that doesn’t mean it’s difficult to use – the workflow is rapid and efficient once you grok the UI elements and it becomes second nature quickly. (You might need to squint at the UI a little, but fortunately, the window is resizable.)

I almost hesitate to reproduce the specs, because I think this is more than the sum of its parts. Let me try to sum it up first: imagine a really grungy digital synth with some edgy wavetables, plus FM (with multiple modes, including nonlinear), plus nicely modeled low pass gate, and then extra filters – dual highpass/lowpass, variable width bandpass, and 6x bandpass filterbank. And you’ve got some bitcrushing (sample rate and bitrate reduction) for extra edge, plus additional saturation. That’s more than enough filtering and wavetable goodness to make an array of melodic and percussive sounds.

Here’s a quick video of me jamming with that sound engine to give you a taste:

Now, that alone is already the makings of a useful sound design palette; it’s very much like what I tend to patch together when I have access to a modular. (I really look forward to combining this with V4-CO / GLITHc for added mayhem.) But this wouldn’t be a Cong Burn joint without some additional layers. So you get a very nice algorithmic/convolution reverb with multiple routing modes and spring reverb, stereo/ping-pong delays and frequency shifter.

And then comes the “stacking” bit: you can build complex polyrhythmic ratcheting chord sequences – in a way that definitely requires you watch the video tutorial. You can grab samples (permanently stored on your hard drive), then slice and granulate them. And you have the ability to modulate anything with anything else – there are two step sequencers, six chaos generators / LFOs (with different modes like “flutter” and “ripple”), per-stage parameter locks, and an attack decay envelope, all freely assignable. You just click the modulation toggle above the modulation source, then drag the range of the parameter. That gives you the kind of patching flexibility you’d have with a modular, but in a Massive-style software paradigm. It’s really addictive, and with the sequencers and unique LFOs, you can quickly build up interesting patterns.

Combine that with the recorders, and you can continuously grap loops and bounce down ideas. You can drag these into your host, too – so it’s a perfect combination with Ableton Live, as you can keep capturing loops to use later. At the same time, it’s compelling enough that you can just use it as a synth and ignore the loops if you want.

Here’s a few moments of playing with that layering capability:

Either way, this is a brilliant way to build sounds and ideas quickly. Cong Burn has found a clever solution to the problem that plagues computer production. We have these great synths that we love to endlessly tweak, but we can get lost in them and lose the great moments. Stacks is an environment that turns all that tweaking into song materials. And it makes all of those tweaks dynamic, so that even without recording and looping, the synth engine in Stacks never has to be stuck in a rut.

There are also some nice tuning capabilities, even if I’d love to see full Scala and polyphonic pitch bend support.

You can route MIDI into Stacks — I even tried modulation from the host, even though you don’t need more. But it’s also a MIDI source. There’s really no workflow Stacks can’t fit.

If I had any complaint, it really is that I’d love the UI to be easier to see. The interface could also really use some interactive documentation or a more complete manual. But I hope that won’t discourage you, as I think you’ll find a lot to love in Stacks right away – and after watching the intro video, I found it easy to experiment. The couple of confusing interface elements become clear right away once they’re explained.

Do watch that full video for a sense of what this is about – and how you can make entire tracks this way. (That means the iOS and desktop versions work well in concert, too – and naturally, you can just work entirely on an iPad with the mobile version if you prefer.)