The NEXUS Interface Card for Integrating External Devices with ADAT Toslink Port into the System

With an XAF card it is possible to integrate devices with a Toslink optical port in 8-channel ADAT format into a NEXUS network. The card has an input and an output and processes a total of 16 audio channels.

The XAF board offers a Toslink input and a Toslink output. Audio is transmitted in ADAT format so that a total of eight input and eight output channels can be connected to the NEXUS network via the board, while a DSP is integrated on the XAF board, which can handle requests between 24, 20 and 16 bits if required. A dithering option is available to minimize quantization distortion in the form of overtones.

In addition, noise shaping can be activated to shift the noise energy to areas that are less sensitive to the human ear, and is optionally available with sampling rate converters that can be activated separately for input and output. It is possible to synchronize the output to the input directly on the board, but to convert the signals in the direction of the NEXUS network via the SRC.

Integrated DSP

When the audio signal is requantized to 20 or 16 bits, a dithering algorithm is executed to avoid rounding errors. In addition, the Noise Shaping function allows the noise energy to be shifted to an area where the human ear is less sensitive. These processes are calculated on an integrated DSP.

Optional Sample Rate Converter

The optional sample rate converters in the inputs can be switched on manually or operated in auto mode; the board then automatically detects whether the incoming frequency corresponds to the NEXUS system clock.

Adjustable Digital Gain

For all inputs a digital gain with 20dB of gain or attenuation adjustable in 1dB steps is available.

Switchable Phase Inverter

A phase inverter can be connected downstream of each input channel.


Connecting Devices with ADAT Optical Interface to NEXUS Networks

Although in use for a long time, the ADAT optical interface is still used as a digital multi-track interface for audio devices. With the XAF card, eight freely selectable audio channels can be output from the NEXUS network and incoming ADAT data streams can be received. The included sampling rate clock can also be used as a synchronous source for the entire NEXUS system.

Technical Specifications :


XAF_01 1 x 4TE
Toslink 1x ADAT Input
Toslink 1x ADAT Output

Technical Specifications


Data formats ADAT
Audio data 24 bit, 20 bit and 16 bit
Sample rates 44.1, 48 kHz; 32 kHz (special version); variable (w/ SRC)
Output configuration Transparent forwarding of all ADAT-format user bits (with SRC disabled), re-quantization to 16-bit and 20-bit output formats using noise-shaping and dithering algorithms
Indicators PLL-status LED
Gain adjustable ±20 dB for the inputs
Latency 4 samples (w/o SRC); 0.7 ms (w/ SRC, typ.)

Operation Conditions

Temperature range 0° C to +50° C
Max humidity max. 90 %, non-condensing

Storage Conditions

Temperature range –35° C to +70° C
Max humidity max. 90 %, non-condensing

Power Supply

Voltage +4,75…5,25 V
Currrent 500 mA

Mechanical Data

Weight 0,235 kg 
Downloads :

NEXUS / NEXUS Star Technical Specifications




XAF Technical Specifications