I plugged guitar via USB external audio card U24XL to Mac OS X Yosemite. But I can't hear any sound of it in GarageBand. I set up input/output in GB's preferences, and marked the current (guitar) track for monitoring, but no sound of guitar is listenable, nor recordable.
Output is correct as I can hear a drum track. The audio card works fine because I can monitor raw guitar sound via a tiny utility
LineIn (I can record it in