Take a look at this great introduction video which explains how it works:
And here it is linked up to the Doepfer DarkEnergy synthesizer:
I would say that the SQ1 is best suited for experimental electronic musicians who want a convenient and affordable way to bring sequencing into their live set. Its compact size, hands-on interface, and ability to connect to any synthesizer, means that you can easily manipulate sequences in a live setting.
Not only can it connect to standard MIDI and USB MIDI to control digital equipment, there are two CV/Gate out channels, littleBits out (so that you can connect to the synthesizer kit made by littleBits), as well as the SYNC IN/OUT for connecting to Korg’s own range of miniature synths such as the Monotribe and Volca Keys.
Although you don’t have the infinite possibilities offered by computer software sequencing, as a hardware step sequencer the SQ1 does offer some surprising versatility. There are two sequencer channels, A and B, each containing 8 steps. You can either run them one after the other as a full 16-step sequencer or run them together. Not only that, you can also set it to alternate between them or sequence the steps totally randomly, which is great for the more experimental musician.
You could be forgiven for thinking that the SQ1 was made many years ago, due to its sturdy metal construction. Many electronic products these days are mainly built from plastic and, therefore, don’t last. The SQ1 has been designed with the traveling electronic musician in mind