Since the biphase format is a self-clocking signal (meaning no separate clock signal is needed) only one signal conductor and one ground are needed to make the connection. The signal will look something like the bottom signal in the picture below. This combination of biphase data packaged with the defined channel encoding is called S/PDIF which stands for Sony/Phillips Digital Interface. Both stereo channels are encoded in this digital bit stream along with sync bits which allow the receiving device to synchronize with the signal. The digital coax signal is a series of “1s” and “0s” (or high and low voltages) output in what is called a bi-phase format. The output connector is a single RCA connector which usually has an orange colored center insulator. The output is usually connected to an amplifier, an external Digital to Analog Converter (DAC), or to a powered speaker like the T1 that has a built in DAC. It can be found on some computers and other dedicated music sources like the Sonos Connect wireless receiver. If noise is induced on the analog signal it manifests itself as a “pop” or “static” sound in the speakers.Ĭoax – The digital coax output is probably the least used output on music sources today.

It looks something like this on an oscilloscope. The analog signal is a varying voltage which is changed both in level and frequency to replicate the music. The output connector is usually either a 3.5mm stereo jack or a pair of RCA type connectors. In the case of the computer, this output is generally connected to a set of powered computer speakers. This output is usually connected to a set of headphones or ear buds in the case of the mobile phone and mp3 player.

Every mobile phone, mp3 player or computer has an analog output. Analog – The analog output is probably the most common output on music sources today.

Usb to digital optical converter