Pschimel,

How to produce a true 'silent voice' from the 740 looked impossible untill Dr. Simon Williams at another forum solved the problem. You can use either the R1 or the R2 voice. For the one you chose, say R1, assign 'Organ Flutes' to it. Then set all the pipes volume down to zero. There is an 'organ flutes' dedicated button that brings one to those settings. Set voice R2 to Off, then save it to a Registration Memory button (say no.1). So when the MIDI data goes out, the PSR is playing but produces no sound locally YET the foot volume 'raises' the volume up and down. Of course the external module will obey the commands. Assign the foot volume control to voice R1 also. To play a mix of a local voice and the external box, use another registration button in which R1 is the external box and R2 is any one of the arrangers boxes, for that both R1 and R2 are On, of course.

The difficult part was that special use of the Organ Flutes with each pipe set at zero volume. I had gone nuts trying the mixers and all other parameters but it wouldn't do it. I also set the volume pedal as Master and get good expression control from the B4.

Of course the only voice you couln't combine with would be Organ Flutes. I liked the B4 combined with the XG sweet alto sax set at a rather low volume. Hope it is clear or gets you started?