So- try not to take this the wrong way. I’m not trying to be snarky.
a) which MIDI controller would totally matter, if this were a real problem. Some use PC, some CC, some send ‘ACTIVATE ccs.. etc.
Luckily yours really just does it one way- a PC message.
But
b) I don’t think its real.. and Ill tell you why- I think you are observing normal operation when switching presets- NO SPILLOVER.
I think when you are switching using the KNOB (not the buttons, like in your OP)… there is a little delay before the preset actually switches… and you are hearing what you ~think~ is a tail.. but really the preset just hasnt switched yet.
But you dont need to believe me- lets test:
Please check using the BUTTONS on the H9.. not the knob. See if you have spillover. Do us a favor… use a LONG delay with A LOT of decay… so you can really tell it is getting cut off.
THEN.. check with the knob. Try to note when the preset ACTUALLY switches, not when the Display switches. (Note- This delay is so you can scroll from preset 1 to preset 50 by jog-wheeling there.. without hearing all the presets in between. It is normal)
Now- do you have spillover?
IF YOU DO.. THIS IS INCREDIBLE…And we need you to contact Eventide. They need to do a firmware dump on your particular H9 and figure out the code-mutation that makes this possible.. so we can ALL have it in a future update. Please do this as soon as possible.. as this is a feature many, many people want.. but had been put on the ‘Impossible” list.
Please let us know what you find.
