The Solo is designed for use by a single musician. There are two analog input channels, and two digital ones. The onboard mixer has four input channels, which can be summed to the analog input channels. Both the analog and digital inputs can be used at the same time.

There are two balanced analog output channels, which are then split between the monitor outs, master outs and both headphone amplifiers. The Solo is designed for mixing to take place in your digital audio application, so no more than two output channels are required.

The number of tracks is only limited by your digital audio application and computing horsepower. (Emagic Logic Audio on an Apple Macintosh G4 supports 128 audio tracks.)