Pro Tools | MTRX is fully modular, enabling you to customize it with up to eight analog and/or digital audio I/O option cards to create a 64-channel interface for Pro Tools | HD. You can install a maximum of six AD and/or DA cards to support up to 48 analog channels. Or design an all-digital box-or any combination between. Just start with the Pro Tools | MTRX base unit and go from there. Or design an all-digital box-or any combination between.