Chuck...I do not change the midi setup at all... It is always on All Keyboard setup... The Gem module changes anytime I make a change to my setup on the T4... If I change presets or adjust the volume on any of the voices (r1 r2 r3) the volume drops on the module.... I also lose the reverb.... The Yamaha tech had me try several things but decided only if I turn off Program control would it work but then no susstain.... thanks Ron