Thank you Gkellum for your answer. It sound clear now…

Any chance that one day Eventide create a stompbox with the ultra-shifter algo inside ? A human voice oriented effect box (and saxophone also) ?

It could be a very interesting choice singers and saxophonists like me …

Or another dream : just develop an algo for the H9 inspired by the ultra-shifter !  Using it with the Mixing Link could be a very good solution for singers…