There are a few solutions:
- Make it generate a more normal 24PPQN. I like the idea of reworking its clock, speeding it up and dividing down internally. Maybe generate start/stop signals from the buttons then have a full DIN sync.
- Add a clock/sync in. Slave it to something that makes a better master clock and/or is MIDI compatible.
- Add trigger ins. The problem with both of the other approaches is that you still have to use its internal, very limited and fiddly sequencer. This avoids the clock and sequencer entirely. Trigger ins cure all ails.
Triggers it is. This is a pretty simple mod: just disconnect the TC5501 RAM from the sound generator and connect your triggers. This has already been documented here, but I found the images unclear. Since I'm performing the same mod, I used the opportunity to take my own pictures.
First cut out the TC5501 that generates the triggers. Just sever its data lines: pins 10, 12, 14, 16.
Then solder wires for the new jacks. Red wires are the original trigger outputs. White wires are the trigger inputs.
Attach switched jacks such that the original triggers are used in the absence of external triggers. Ground to the ring, red to the switch, white to the tip.