1. I have just tested with only one H9 and the POP sound is just the same! I thought I have a faulty H9, so I tested with the other one as well, and the POP sound occurs again, when switching from a preset POST to a preset routed PRE (not the other way around).

2. Did you verify my claim in your testing setup? You only need an amplifier with Loop, so you can verify it yourself. Does it happen to you as well? For this mono test I used the wiring as described in your page. In fact, my wiring with 2 H9’s is just the same, except they are put in series, as in my diagram. So… 2x H9’s and an amp is a “complex setup”?!?

4. Could you be a bit more explicit about timings when switching with midi?

5. Is this POP sound “normal”? Would you use pre/post per preset in a live performance, with this pop sound occuring?!?…