Ok, we're finally getting somewhere:
– the expression pedal is working correctly now. Somehow the EV-5 didn't like a mono cable into a stereo input jack, not sure why but it's working now with a stereo jack on one side of the y-cable only soldering the tip and sleeve. I get a nice 0 – 100 on the display of the H9 when going from heel to toe.
– my aux switch still doesn't! work on the other side of the y-cable for Tap tempo. Exptip set to both and aux switch – Tap tempo set to ring. The H9 sees the first press showing the bpm value but ignoring any new presses on the switch.
If I set the H9 to be controlled by an aux switch (Exptip) and connect a mono cable between my aux switch and the H9 -> the tap tempo switch works correctly changing the bpm value. The midi clock is also send to all my other devices then.
The aux switch I use is of type momentary like used in a lot of pedals that have a tap tempo switch (soft touch).
BTW, another important thing is that the aux switch works perfectly fine for controlling the PRG+ or Bypass when connected via a Y-cable. Not sure why the Tap tempo doesn't work?