Here are some answers for you, Mark. I have both the SOL and PR300s. No, you cannot use the 3 MIDI couplers on different channels simultaneously to use distinct patches from the SOL on each division. On the disks 1-5, whatever sound you select to use, say Spanish Trompet, it will sound on all your midi pistons--on the 577--that stop will play on the SW, GT and Pedal. On my organ which has a midi A and B piston, it only sounds on the A piston, so you can use the B piston to select sounds from the PR300s. Disks 6 and 7 contain sets of sounds, for instance, "gospel organ" or such. So the sounds on disk 6 (organ sets) and disk 7 (orchestral sets) will play different on each division. You will have a different sound on the SW-GT and PEDAL. on the 577..but you cannot use sounds from the PR300 when you use these 2 disks. I like the Dulzien stop (#7 on Reed disk). This dulzien will play the same on the SW -GT-or PED when you have the midi piston engaged. But you can play it only on the SW, and use your organ stops on the GT and PED for a nice effect. The SOL is nice, but somewhat limited in that you can't use different sounds at the same time-or sounds from different disks. But, it does add a little more to your organ...especially if you don't have a 32' in the pedal. Clark Haney Wells Tahoka TX ____________________________________________________________________ To unsubscribe or set to vacation, go to www.frogmusic.com/rodgersmem.html If you have any difficulty with this or PayPal, please contact noeljones@xxxxxxxxxxxxx for help! Shop for Playing Guides to your Rodgers Organ at Frog Music Press