The nABC by Stockholm based Suonobuono is a compact and lightweight hardware sidechain compressor that has a few tricks up its sleeve. It has a stylish brushed aluminum enclosure and features a large rotary encoder and a row of touch controls for its interface. A ring of multicolor LEDs surrounding the encoder provide visual feedback as well as indications of settings.
Powered via USB [cable included], the nABC can run off of any USB host port that provides 5V and at least 1A. It is a pretty compact unit at about 6-inches square by 2-inches deep and is sturdy but lightweight. Its small footprint makes it relatively easy to find a spot in even the most crowded studio or live [streaming?] rig, and all connections are on the rear of the unit and include 1/4-inch jacks for the audio in and out and 1/8-inch [3.5mm] for gate inputs and external sidechain audio or CV. There is also a MIDI input which works with the included TRS to 5-pin DIN adapter cable. It operates in one of four different input modes—many of which have overlap—and provide a wide range of options for working with the unit.
nABC's sidechain compression can be triggered and controlled by any number of input combinations—responding to an audio signal on the external audio input, via MIDI, or even analog gate and CV signals. It can also be utilized as a traditional compressor with the compression being triggered when the Line In audio exceeds a threshold.
I've never been one to use extreme pumping sidechain in my music but I have to say it sure can be fun. That being said, using the nABC in a more subdued manner can add some really interesting and musical movement to any piece of music. The possibility of utilizing MIDI [or analog gates and CV] to trigger sidechain and control its depth [based on note velocity] opens up some interesting possibilities for experimenting with the effect. Triggering with a sequence [of gates for sidechain and CV for depth] that is offset or different rhythmically than an arpeggio or melodic sequence is a great way to inject some interesting variety and rhythmic variation. Experimentation is key to finding the right combinations but the exploration is damn fun. Not only that but utilizing the compressor in this manner is a really nice way to carve out space and give prominence to parts of a mix in a dynamic and subtly rhythmic way.
The experimental potential extends to the analog realm as well. Because the nABC is DC coupled you can mess around with adding the sidechain effect to give rhythmic qualities to all sorts of CV signals. I had a ton of fun trying out the nABC on all kinds of modules in my rack. Even running in a straight DC offset and getting the nABC pumping was a fun-albeit inefficient way of creating an LFO. Adding rhythmic squashing to LFOs or complex envelopes has never been easier and the immediacy of the nABC is one of it's strongest features, especially for a performance system or for those who prefer to go as DAW-less as possible. The rotary encoder also functions as a bypass switch and adds a nice performative aspect to the nABC.
The nABC’s operation is very straightforward and with its generously proportioned controls doesn't feel fiddly or cramped and it plays well with both Eurorack and gear of the non-Eurorack variety. There are alternatives for getting sidechain compression into your rig but you'd be hard pressed to find one that is as easy to use, fun to jam on, or as few HP as the nABC.