So, here is what I am trying to setup:

Voodoo Lab Ground Control Pro transmitting MIDI PCs to SV on MIDI Ch 1, and also transmitting MIDI PCs to M13 on MIDI Ch2, so that I can change SV patches and M13 Scenes with one footswitch from the GC Pro.

Here is how I have it setup:

GC Pro MIDI Out>>>SV MIDI In

SV MIDI Out>>>M13 MIDI In

SV MIDI Out is set to "Thru" in the SV's menu.

SV MIDI Channel is set to 1

M13 MIDI Channel is set to 2

This is how I think it should be setup to work, so that the SV will listen to the PCs sent by the GC Pro on Ch 1, and pass through the PCs sent by the GC Pro on Ch2 to the M13.

But it doesn't work.  When the SV MIDI Out is set to "Thru", the GC Pro will change the Scenes on the M13, but will not change the preset on the SV.

However, if I change the SV MIDI Out to "Out", the GC Pro will now change presets on the SV, BUT it will not change Scenes on the M13!!

Why does changing the SV MIDI Out setting between "Out" and "Thru" change whether the SV is listening to its MIDI In?

It's as if when the SV MIDI Out is set to "Thru", it stops listening to its MIDI In - the MIDI In only works if the MIDI Out is set to "Out", but of course when it is set to "Out" is does not pass through the other MIDI info from the GC Pro.

Is this the intended design of the SV (and if so, Why?), or is this a bug/problem with my head?

Thanks!