How is this tuning happening?

around 11:00 he changes the model from “green 1” to “green 5”, and the cable is moved from harmonics to timbre.

green 1 “Virtual-analog synthesis of classic waveforms.”
green 5 “An additive mixture of harmonically-related sine waves.”
see the manual

If you’re going through the Audible Instruments plugin, this may come in handy, if trying to tune the models: