This patch was made with the idea of swelling in multiple chords quickly. Most auto swell features I’ve played with have the problem where after the initial swell if you play too quickly the next chord wont swell. I still have some fine tuning to do on this but what it does is – an onset detector is connected to a sequencer that switches an audio channel in to three outputs going through 3 different VCAs. The sequencer also triggers 1 of 3 ADSRS controlling the swell length. Default setting has each swell getting slower but you can make them all the same by setting the ADSRs to the same length.

Page 1 – Audio Input to Audio out switch and Onset Detector(adjust the sensitivity for your instrument)
Sequencer triggers the audio out switch. Audio Output at bottom.
Page 2 – 3 VCAs into a ghost reverb
Page 3 – ADSRs for each of the three VCAs

There is probably a less DSP intensive way to do this, I used ADSRs instead of envelope filters for ease of use.