just as I wrote in an earlier post:
VAL = xx
CHK = z4
your SysEx messages are missing the value and checksum parameters. Instead, in their place you only have a 00 value…
Try this for lower partial 1 frequ:
F0 41 00 14 12 00 01 4D xx z4 F7
xx will be replaced by Ctrlr with the current modulator value
z4 will be replaced by Ctrlr with the calculated Roland checksum
Another question at this point: Have you ever successfully sent ANY MIDI message from Ctrlr to the D-50?
For example, place a uiMidiKeyboard on the panel and hit a note. Does the D-50 play?
I am still convinced that your message setup is correct (F0 41 00 14 12 00 01 4D xx z4 F7), but there´s a general communication prblem…