# Configuring Digital I/O Formats

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Setting the Optical I/O Format

When using an optical I/O Module, set the format of the optical inputs and outputs to either ADAT/SMUX or S/PDIF using the Optical Format drop down menu, found on the Device Settings tab. The following format selections are available:

> ADAT - This format transmits 8 channels of digital audio over one Toslink (optical) cable at sample rates of 44.1 to 48 kHz. The ADAT format, originally found on Alesis ADAT digital recorders, is found on a wide array of digital devices such as keyboards, audio PCI cards and audio interfaces.

> SMUX - This format transmits 8 channels of digital audio over 2 Toslink cables at sample rates of 88.2kHz to 96kHz. The SMUX format,an extension of the ADAT format, allows the transmission of digital audio data at higher sample rates.

> S/PDIF - This format transmits 2 channels of digital audio over 1 Toslink cable at sample rates of 44.1kHz to 96kHz. S/PDIF optical format connections are often found on keyboards, CD players and other consumer audio devices.

## Using the S/PDIF Coax I/O

The S/PDIF Coax format transmits 2 channels of digital audio over 1 coaxial cable at sample rates of 44.1 to 192 kHz. S/PDIF Coax format connections are found on audio PCI cards, audio interfaces, digital effects units and CD players.

> S/PDIF Coax Input

> Symphony I/Oʼs internal architecture employs 16 channels of input and output per I/O Module. Since the S/PDIF Coax Inputs are the 17th and 18th inputs, itʼs necessary to replace a stereo pair of analog or digital inputs with the S/PDIF Coax Input in order for the S/PDIF Coax Input to appear on the Routing tab grid. Use the S/PDIF Coax Replaces drop down menu, in Maestro's Input tab, to select the analog or digital input pair to be replaced by the S/PDIF Coax Input pair.

> S/PDIF Coax Output

> The S/PDIF Coax Output is "tapped" from one of the other analog or digital stereo output pairs. Use the S/PDIF Coax Mirrors drop down menu, in Maestro's Output tab, to choose which analog or digital stereo output pair will be duplicated on the S/PDIF Coax Output.

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