hello,

Whenever I connect my Casio CT-680 keyboard into the MIDI in on my MC-303, everything I play is at a significatly lower volume level than the parts I play on the "keyboard" on the MC-303. Any ideas?

Does the CT-680 have velocity sensitive keys - ie the harder you hit them, the louder the sound from the keyboard? The 303 is velocity sensitive, so that may affect the sounds. Try either hitting the keys harder or, if the CT-680 has the necessary controls, alter the default velocity on the Casio. On a standard midi-controller keyboard you can do this by hitting the "midi/select" (or equivalent button), select the key which is mapped to velocity (normally there are labels above each key) and then slide the midi controller (if you have one) up as far as possible.