Sometimes I practice on and use an 88-key Casio Celviano digital piano that also doubles as my MIDI controller. I occasionally use this digital piano to create piano audio tracks in Logic Pro by using the headphones jack to send the signal to my x1204usb interface in stereo.
Step #1: Plug the single end of an 1/4 inch cable into the ‘Phones’ input on the digital piano. See the photo below.
Step #2: Connect the 1/4 inch dual ends of the cable to channel 5/6 on the x1204usb interface. (You can also use channel 7/8.) See the photo below.
Step #3: Make sure that the ‘2-TR/USB TO MAIN’ red button is NOT pressed down.
Step #4: To adjust the volume of the recording, you can play around with turning the volume knob on the digital piano and/or adjusting the ‘MAIN MIX’ R/L faders on the x1204usb. See the photo below.
Step #5: Make sure that the audio interface is connected to the DAW. In this specific scenario, I’m using Logic Pro 9 on an iMac.
Step #6: In Logic Pro, follow the navigation in the photo below to change your audio preferences.
Logic Pro —> Preferences —> Audio
Step #7: Select the ‘USB Audio CODEC’ option for the ‘Input Device’ field. (I have this same CODEC option selected for the output device since I like to listen to my tracks through my Yamaha HS8 monitors which are also connected to my audio interface.)