Power Mac G5: Optical Audio Port Specifications

Power Mac G5 computers have two optical audio ports of a type new to Macintosh. They allow you to connect a variety of audio equipment using digital optical (a.k.a. "Toslink") cables. Cables with Toslink connectors are the style compatible with the Power Mac G5 computer. These optical audio ports allow the transfer of stereo audio or encoded 5.1 audio (commonly found on DVD movies).




Figure 1 Optical Audio Ports

The specifications for these ports are:

Data format: Sony/Phillips Digital Interface (S/PDIF) protocol (IEC60958-3)
Connector type: Toslink optical (IEC60874-17)
Bits per sample: 16-bit or 24-bit

Optical digital audio out

Note: Specifications are based on a typical situation with playback of a 1KHz, -1dBFS 24-bit sine wave, 44.1Khz output sample rate, unless otherwise specified below.

Output sample rate: 32 kHz, 44.1 kHz or 48 kHz
Signal-to-noise ratio: Greater than130 dB
Total harmonic distortion + noise: Less than -130 dB (0.00001 percent)

Optical digital audio in

Note: Specifications are based on a typical situation with playback of a1KHz, -1dBFS 24-bit sine wave, unless otherwise specified below.

Fsi-input sample rate (external clock mode): 32 kHz, 44.1 kHz or 48 kHz
Fsi-input sample rate (internal clock mode): 16 kHz to 96 kHz
Signal-to-noise ratio (external clock mode): Greater than130 dB
Signal-to-noise ratio (internal clock mode, 16 kHz < Fsi < 96 kHz): Less than -112 dB
Total harmonic distortion + noise (external clock mode): Less than -130 dB (0.00001%)
Total harmonic distortion + noise (internal clock mode, 16 kHz < Fsi < 96 kHz): Less than -112 dB (0.0003%)