4ms loves symmetry, and quite a few of their modules, like the Shaped Dual EnvVCA, Stereo Triggered Sampler, Dual Looping Delay, among others, are beautifully symmetrical (I heart symmetry). Well, they’ve taken this concept to a new level where one module can be two, with their new Catalyst module, based off of the Emblematic Catalyst. With just a quick three-button press and a flip of the faceplate, you can switch between the Catalyst Sequencer (CatSeq) and the Catalyst Controller (CatCon).
Starting with CatSeq, the first thing you notice is that it doesn’t look like your traditional sequencer. With its multi-color light up potentiometers, a bunch of buttons, and a big ol’ crossfader smack dab in the middle—but no screen—CatSeq eschews the look and workflow of most modern Eurorack sequencers. A clock-based (with tap-tempo) eight-channel sequencer, where each channel can output either CV or Gates, CatSeq sports a crossfader that can scrub through the steps in a sequence, with up to sixty-four steps available. You can customize each of the channels in terms of start point, direction, length, phase, voltage range (-5V to +10V), BPM/clock division, transposition, and per-step probability with per-channel randomization. Each sequence can be quantized to various scales, and you can also add glide to each step. In short, you can have eight independent channels of CV or gate running at different lengths, in differenat scales (for CV), in different directions, with randomization/chance for each, and at different divisions of a given clock, with all options signified by the multitude of colors of the illuminated potentiometers. If outputting gates, each channel can be customized for gate length, +/- swing, glide, ratcheting, probability, and randomization. Some of these are global parameters—like phase, start point, and length—but all can be customized/overridden for each channel with a button combo. You even have CV control over the reset and can do the cut/paste thing to make longer sequences easier to create. It’s easy to save and recall sequences (up to eight of them) as well. The world of CatSeq is your oyster, and you can customize until your heart’s content.
Getting started with CatSeq is pretty quick. Figuring out the editing structure so that you know what channel you’re on, and what page in that channel you’re editing is fairly painless, though it did take me a minute to get it straight initially. I didn’t have an Aha! moment so much as I had a No Duh! moment, as once I found my way around, it more than made sense and was easy to navigate; 4ms has done a good job with making this intuitive. For example, when you’re adjusting the amount of something, the brighter that the potentiometer lights up, the stronger the signal: a faint glow when you’re adding glide to a step means a subtle slide, but a brightly lit pot means you’ve got your glide on full-strength. That's pretty easy to remember. Even for things like the amount of ratcheting for a gate, where you can’t quite tell how many ratchets are there, you can still see via the pot brightness more or less where you’re at. In a dense patch, it would be nice to be able to view the levels more precisely, but part of the fun of CatSeq (and CatCon) is the ease at which you’re able to move around, play, change things up, and go from part of a sequence to another; in terms of pages via the page buttons, and with the crossfader in terms of steps. It’s not that you can’t dial in something specific—you most definitely can—it’s just that what CatSeq offers in the ease of real-time performability, it loses in the ease of specificity, and dialing in specifics without a screen can take more time.
I use sequencers a lot in three different scenarios: as a set-and-forget tool, as a performance-based tool, and for drums. CatSeq works great as all three. In the case of the first two uses, there is plenty here for using CV for melodies and parameter changes, gates for triggering an event or effect, and a ton of hands-on (or off) controls to tweak, with the crossfader being the most intersting and obvious one. As an instrument, I would tweak, change, and just mix things up, moving around steps and changing direction, scale, glide....I love sliders already and found the physicality and instant gratification of the crossfader to be fun, fast, and furious. This phasing of the sequence can even be CV controlled for some hands-off jumping around. Using CatSeq as a drum sequencer, triggering percussion-based modules, pinging filters, or using it to trigger an EG or VCA to craft drum sounds was excellent, though I found CatCon to be more of my liking for this use, but more on that in a bit.
Once you understand the navigation, CatSeq becomes an incredibly playable sequencer and nothing can hold you back. It might take more time to dial in the minutiae due to not having a screen, but in no way do I miss looking at a screen to figure out what the voltage range is or to figure out what scale I've chosen. For example, in Lydian Dominant mode, the pot lights up a salmon color. Salmon-colored LEDs? Who even knew a pot could light up salmon?!
As mentioned, take off the faceplate, flip it around, and hold down the three buttons on the right side of the module (Shift + Tap Tempo + Channel) and you’ve transformed your module into the Catalyst Controller, an eight-output macro controller. I really thought the CatCon would be something fun to try before going back to the CatSeq, but with that phase scrubbing crossfader and eight outputs of CV or gates to control parameters in a patch, CatCon was way more fun and useful than I’d anticipated.
Both modules share a lot in common aside from their layouts being the same: they have the same number of channels (eight), both can output CV or gates, both can be quantized in the same way and with the same scales (remember…salmon for Lydian Dom.!) and both can scan or scroll through the steps (or scenes, in the case of CatCon) of a channel with the crossfader or patched in CV. There are other similarities as well, but the differences here are more important, with CatCon being kind of like a preset/scene manager where you configure a certain amount of voltage (or a gate) to control part of a patch like filter cutoff, VCA CV amount, turning an effect on and off, etc.
However, CatCon is kind of like a sequencer, where the eight channels output an amount of CV or gate, but instead of steps, you can configure up to sixty-four scenes on what’s called the "pathway." It’s like steps on a staircase: sometimes there are eight steps, sometimes fifty-two—however many you’d like—but no matter how many steps there are, at each step you can set a new CV or gate value to change up any given parameter in another part of your patch. Like the CatSeq, you can scroll through the various scenes, and this movement is where you can get bonkers. You can get as detailed as doing a sixty-four-scene frequency “sweep” of your favorite filter; or do the opposite: only open and close that filter in a two-scene path, with just the fully opened and fully closed CV values as the output of a given channel. You can trigger something with some gate action for turning off and on a particular parameter (like reverb) and you can add slew (up to two minutes!) to delay those transitions. In a big patch, you can change a whole lot at one time with little effort. Whether it’s moving from one point on the pathway via the Scene buttons or the crossfader (or CV) to another for an immediate and lasting change, or non-stop motion of the scenes to create frenetic movement, it’s hard to overstate how powerful this can be. You can add and subtract scenes, copy and paste them into other slots, and save and recall them as well, with the same operational techniques as CatSeq. The real kicker is that you can record up to ten seconds of the crossfader and CV motion to create unique modulation. This recording can be triggered manually, randomly, or be synced to divisions of a clock input for more (dis) orderly fun. CatCon also lets you configure how it morphs between scenes, so you can have a sharp change from one scene to the next, or move along the pathway with interpolation between scenes for smoother transitions.
None of the macro controllers I’d previously played around with have near the capabilities that CatCon has, and it’s a lot of fun to pile it on; controlling cutoffs, triggering effects, switching waveforms…there’s no end to what you can control. And with eight channels, eight things you can control at once, you can be subtle with the crossfader, inducing multiple tasteful changes with one slide, or chaotic, constantly jumping around to the point of indistinguishability. Using it to control a drum voice, in my case a combination of Modbap’s Trinity and Winter Plankton’s ZAPS, was amazing. Using some channels on CatCon for gate duties and others to alter the sounds of the two modules, the variations on both rhythms and sonics were vast, and recording the movement of the crossfader and looping it, with the ability to re-record a different movement on the pathway on the fly, was nothing short of scene-stealing. I found myself so enamored using CatCon for drums it was easy to see how two or more of this module in a big patch, with one dedicated to drum/percussion use, and another to control other patch parameters, could be really valuable.
Both the Catalyst Sequencer and Catalyst Controller are good fun, and man, there is so much that lies beneath the surface of each. 4ms have hit this one out of the park, over the lights, and beyond the parking lot. What we've got here is a dual threat that is hard to decide how to use, because both modules are so versatile. Lucky for us, we don’t really have to make the hard choice since we have the ability to change from Catalyst Sequencer to Catalyst Controller, or the other way around, or you know…just grab two of them.

Price: $395 each

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