I want to control the CV-in/expr-Pedal in on some (guitar) effect-Pedals by max. Those usually need a CV (control Voltage) of 0-5V. I could buy a midi-to-CV box, generate midi and "translate" it in CV, but I thought I could generate this directly in MAX. Expert sleepers have plug-ins which do that, using the audio output of (some) sound cards. Fine.
But what, in MSP, is a 0-5V signal???? A frequency? what pitch(es)? an amplitude? something else? how for exemple create a slow 0-5 sweep (which could then be the WWWWWHHHHHHHAAAAA of a Wha-wha)?
a wha-wha on your bass? Not sure I will help you for this heresy ;-)
You need to send a DC to your sound card, for instance the output of sig~. In MSP you can set values between -1 and 1 (the amplitude), they will be converted by your soundcard into a CV, but the volt range depends on the soundcard. And some soundcards just doesn’t work with DC (but will work with slow changing values, like a LFO). If you have a RME card, only the headphone output will work with DC (with a range about something like-2 2 V – sorry I don’t have my sound card at hand to test). MOTU cards work better for DC outputs. There are plenty posts on this topic in this forum.