When they designed the S21, DiGiCo pulled out all the stops. A robust ARM quad-core RISC processor puts an abundance of power under the hood. Dual touchscreens supply intuitive tactile control and instant visual feedback. 24 mic/line inputs and 12 analog outputs give you enough I/O to get started, while dual DMI option card slots provide room for expansion. The S21 delivers 24-bit/96kHz digital audio for world-class sound and comes loaded with a complete arsenal of digital effects. A built-in 48-channel USB interface makes capturing any performance easy. Featuring an aerospace-graded aluminum extrusion and rugged polycarbonate overlay, the DiGiCo S21 is a full-featured digital mixer that's built for the road.