DIY Volta - Max/MSP + Audio interface CV output

The main reason I put together the little portable modular rig in the post below was to have something that would be easier to travel with than my tb-3031 rack but still get the live tweak-ability and sound of the 303. One of the biggest sonic features of the 303 is the envelope control over the filter and the accent circuits which are responsible for the punchy, funky acid basslines. I was using Massive through Ableton Live for my basic oscillators and then running the sound out to the waveform processor and wasp filter, with the LFO doing some modulation. I got close, but not quite what I wanted. In order to get the filter accent and envelope working I created this max patch that takes midi in and splits the notes depending on their velocity, to trigger a line~ object connected to my soundcard's output. I'm not sure if this will work with all soundcards, but I'm actually using the built in output of my MacBook Pro and it generates a nice little ramp voltage that I can connect to CV1 or 2 of the filter. End result - not a perfect 303 by any means, but punchy, funky acid basslines for sure. The large rotary control changes the length of the envelopes and the slider at the bottom controls the total amount of output.