A.Yes, you can connect the output(s) of a guitar synth (or a similar unit with a low impedance output) directly to the CM-30.
Note:
If you connect two CM-30 units together using the Stereo Link function,
you can hear the true stereo output of the guitar synthesizer.
See the related FAQ:
Can I use two CM-30 units as simple stereo PA system?
(2006/02/09)