Speed knob switches between the three modes: I, I-II, II. Within the mode the timbre is brightened by turning clockwise.
Depth knob controls dry/wet ratio. The sweet Juno sound is somewhere 12 o'clock.
Audio examples are available on Soundcloud.
Note that the I-II* mode is different from the Juno 60 "both buttons in" mode. I'm not a big fan of the original mono vibrato effect so in this emulation I-II* mode enables both choruses in parallel, similar to the TAL U-NO-LX.
Thanks to Andy Harman and JP Cimalando for Juno 60 chorus research, and Émilie Gillet for stmlib Softlimit function.
Have fun!