How to connect a Roland MC707 and Roland TR8S together. You need a MIDI cable and 2 instrument cables, plus whatever main outputs you use. This lets you use the power of the TR8S to support music making on the MC707. You still have the drums available on the MC707 but now you can use those 2 channels for other sounds, so you effectively add 2 channels to your MC707 as well as all the channels and sounds of the TR8S. This really extends both devices and gives you more rhythm control for your MC707 while freeing up 2 channels for external sounds or even live audio. Plus the synth engine of the MC707 gives you what you’re really missing from the TR8S. The 2 of these together give you a great combined solution for electronic music.