The Progression Preamplifier adds new features previously not included in a D’Agostino preamplifier. Most noticeably, the Progression Preamplifier features an optional digital module. The digital module adds coaxial, Toslink, and USB capability to the analog base model. A fully differential DAC handles PCM signals up to 24 bit/384 KHz and DSD signals up to 4xDSD (11.2 MHz). This digital module feeds a discrete, fully complementary and balanced analog signal path from input to output. Negative feedback is not used anywhere in the Progression Preamplifier, nor is it necessary. Open-loop distortion is less than < 0.006% and the open loop bandwidth extends to over 100KHz.