CH C1 Dual Monaural Digital to Analog Controller. Three chassis form the foundations of the C1 Mono. Leveraging the technologies from the original C1, the C1 Mono separates the digital processing section from the two analog sections. Dedicated chassis and internal power supplies for each section allow this product to reach the next level of performance in music reproduction. Add another three X1 External Power Supply units and the C1 Mono becomes CH Precision 1-Series’ ultimate digital to analog controller. The C1 Mono inputs are modular like into the original C1, sharing a common platform. Furthermore, stereo C1 Digital to Analog Controller units can be upgraded to C1 Mono.