[sdiy] Korg Volca sync standard

[cheater00 .]

Hi guys,
I have been wondering what the sync signal was used in Korg Volca
series. I'm talking about the stuff working via mini jack. The cables
included are stereo, but are all three leads used?

I've tried syncing two volcas to a single midi clock source. So it
looked like this:

TR-707 --(midi)--> volca #1 --(minijack)--> volca #2

The second volca got tempo information, but it wouldn't start/stop.
That's what I expected, since that's how it works in DIN Sync, and
that's 3 leads too.

I was hoping anyone had insight into this.

Cheers,
D.