With this circuit it is possible to provide a coaxial digital input for the headphone amps HPA V100, HPA V181, HPA V200, HPA 220 and HPA 281.
The coaxial digital input can be used to connect a digital device with a coaxial digital output (often called "S/P-DIF) like CD/DVD-Players or computers. PCM coded 2-channel digital data with sampling rates from 44.1 ... 192 kHz are supported. The electrical characteristics meets the S/P-DIF standard while the incoming data may be "professional" or "consumer" coded.
The built-in digital receiver forwards the data to a separate D/A converter offering 110 dB dynamic range and –100 dB THD+N.
The converted digital data has priority over all other analog inputs and will mute these when valid data is received.