A Roland System 100 (the 104) & System 700 (Sequencers only) controlling a Roland V-Drum Module. As simple as that this guy controls all patterns via CV and muting/skipping tracks and setting the pattern length.
Starts getting musical at 2:35..
Only miss some dynamics – but there are some pots left
All output voltages are 0 – 2 vdc, including the hihat foot controller signal. The snare and crash signals are going to the rim and edge inputs respectively says SuperPussMusic