Mike:

UD commented on this in another thread with the correct answer I think: unlike all keyboard manufacturers, recording engineers realize their music will be heard in both stereo and mono and use phase adjustment tools so their sound is acceptable if heard in either format. My guess is that keyboard manufacturers who provide a true mono output in addition to a stereo output also use some sort of phase adjustment tool on their samples. In fact, just such as device may be the answer to using a stereo keyboard with a mono PAS system:
http://www.littlelabs.com/ibpjr.html



[This message has been edited by The Pro (edited 03-18-2004).]