On Sat, 2009-07-18 at 19:25 +0000, static.people wrote:
> Hi, I succeeded at least!
> Things work well now: the sync signal from poly-800 leads the Boss DR-110 acidlab sync-in interface. As I supposed in another message that interface needed a start/stop signal on the other pin to work, just like other drums machines like korg KPR-77, while stuff like Roland TB-303 didn't need (as far as I can remember): so I used 3 x 1,5 volts batteries in series for that purpose. It seems like acidlab's interface has a logical buffer inside (a 74HCT74 ?) similar to the one you suggested but it should do the additional job of dividing external 24ppqn sync to match internal 12ppqn. So I safely connected it to poly-800 extracted sync-out directly and (courtesy of the start/stop circuit switch) now it works.
> I'm thinking about finding a way to mod acidlab's interface to exclude buffer's internal divider and let it easily switch from native "external divided-by-two 24ppqn to internal 12ppqn" mode to an "external buffered-only 24ppqn to internal 12ppqn" mode: it should be an easy way to double drum machine tempo by a simple switch.
> But I wouldn't be daring too much... :D
Another way would be to use a PLL to synthesize a higher clock from the
lower drum machine clock. A very simple system could be a squarewave
generator running at a multiple of the incoming clock and retriggered by
it.
Gordon