The obvious use for Dark Link is to plug an analogue synth into it via CV and gate, and then you can play it from a MIDI keyboard or a sequencer.
That works.
But there is a lot more to the little box than first impressions suggest.
I have all sorts of equipment, sourced across decades of music-making, and I have always been happy to bend the rules a little to get the most out of everything.
So imagine, if you will, the labyrinth of my modular setup or even the thought of having two 2600 synths working happily with the latest software sequencer (Stepic in my case), with multiple control voltages all neatly sequenced and room left to improvise in real time.
Dark link can deliver a gate (more later) and four separate control voltages from a single MIDI channel. The unit has these labelled, but you can mess with CC values and the Link has a lean function too. You can do pretty much almost anything if you think about it.
It even takes care of my 2600s with their 12V gate preference. There is a simple jumper inside the Link to shift the gate from 5V up to 12V, so no more hogging the preamp to get the 2600 to trigger. CV2 on the link is mapped to pitch bend, -2.5V to 2.5V, but another simple jumper in the Link gives you a more usable 0V to 5V here.
So you can go deeper and do more with it than its size, price, or even the manual suggests. It has transformed what I can do with regard to integrating state-of-the-art and vintage equipment, and always reliably.
Nobody take mine away!