ok now I understand the concept but [there is always a but ;) ] I have a few more questions, hope not to bore you to death ;) --------------------------------------------------------------------- FOR captain Hasting's digital potentiometer circuit --------------------------------------------------------------------- It's a great idea ! Simple, easy to build but how about controlling this stuff ? On what MIDI event does it reacts ? I must confess I have no programming skills (microprocs) and for making patches I'm just using JsynthLib. So is there a possibility to control the externa filter (eg. Moog filter) in the way I'm controlling the internal SID filter ? how could it be realised ? -------------------------------------------------------------------- FOR CV outs with AOU module -------------------------------------------------------------------- It's a bit more compex than captain Hasting's digital potentiometer circuit but also more efficient. The same question: how could I controll the params of CV outs ? since on TK web site there is only a pure schematics wit board layout, and no description how it works or any other documentation, could anybody explain to me how to control this ? thanks fo all the answers, hope this could also help the other members and hobbists best regards, smycza