PA1-REF is a Reference USB and Network Regenerator, a peripheral that shared the same design DNA with the AMC D2. 

It integrates the SOUNDAWARE Patented USB REGEN Architecture,  designed specially for High End Audio System. The incoming USB data are FIFO Buffered and Regenerated via the PA1 built-in High Speed RAM and Low Phase Noise Crystal Oscilator (Temperature Controlled at 40°C). Powered by the supercharged, constant voltage SOUNDAWARE Reference Supercapacitor, its ability to remove the noise and inteference of USB signal, is the best among all the PA1 models.
 
The Ultra-Low-Jitter, Regenerated USB Output signal effectively elevate the digital front end performance. The flagship PA1 is a device high-end audiophile must have.