Hi. As the new owner of a Px560 (coming from a Yamaha MOX8 I want to use an Organ simulator on my iPad controlled via the 560. Iwant to be able to control the volume of the iPad and , for example, turn the piano volume to zero on the Privia whilst I assign a control knob to turn up the iPad organ whilst I use it.i thought it was a simple matter of assigning one of the control knobs to MIDI volume but it doesn’t seem to work. Does anyone have any ideas on how I could do this? It seems so simple in principle but I just can’t seem to nail it! Any help appreciated. (I connect via a Korg key to the iPad rig). Thanks in advance.