2 point FM synth apparently - just won one off ebay - so gonna have a go at messing with the data... one thing that occurred to me - can't u just wire a pot up between the ON/OFF switch in the PSS FM mod - and screw the data a bit more by resisting rather than just stopping it completley ?
:)
i don't know the pss9, but in general : yep ! it works, but maybe not on every connection. with pots more fun !!