The universal AES/EBU input-output boards for the NEXUS Matrix

The XETR AES/EBU boards combine four 2-channel digital inputs and four 2-channel digital outputs on one NEXUS board. Versions with only inputs and outputs are available; versions with XLR or BNC connections offer great structural flexibility.

XETR series cards offer four 2-channel AES/EBU inputs and outputs, each with its own sampling rate converter. NEXUS networks support the transparent transmission of AES additional data (CUVZ) over the network, allowing the inputs and outputs of XETR cards to be used to connect AES intercom systems or for other purposes.

Furthermore, the combination of AES/EBU inputs and outputs on one board allows an input clock that is asynchronous to the Nexus system to be passed through unchanged to the corresponding output, while the input's sample rate converter only adapts the clock to the system clock on the NEXUS side. Of course, the entire NEXUS network can also synchronize its system clock to each of the inputs.

XETR cards are available with XLR or BNC connectors. Inputs and outputs are arranged on separate front panels and can be placed separately within a base unit. It is also possible to operate only inputs or outputs.

Available with XLR or BNC connectors

This module can optionally be supplied with different front panels, the electrical conversion remains the same. The XLR versions are available for balanced lines and BNC for unbalanced cabling as well as a 4HP wide front panel. (When using both the transmit and receive functions, a second front panel is used in both versions, which is connected to the circuit board via a ribbon cable.

Support of S/P-DIF signals

Since the professional AES/EBU signal and the consumer format S/PDIF differ only in the electrical level, the XETR cards offer the possibility to select the type of input or output in the settings. In this way, both formats can be received and transmitted.

Adjustable digital gain in inputs and outputs

For input signals with known understeering, the level can be digitally amplified by 20 dB. A reduction is also possible. A switchable limiter protects against overload.

Sampling rate converters in all inputs and outputs

The sample rate converters in the inputs can be switched on manually or operated in auto mode; the board automatically detects whether the incoming frequency corresponds to the NEXUS system clock. A sampling rate of 44.1/48 kHz; 88.2/96 kHz or 176.4/192 kHz can be set for each output. In addition, the outputs can also be synchronized to the paired input of the same module.

Transparent transmission of additional data in the AES3 data stream

The NEXUS network is able to transparently transmit an AES3 data stream including the additional data. If no data is available in transparent mode, NEXUS internal data is output. If additional data is transmitted on only one channel, it is transmitted to the other channel.


Variant: XLR 1 x 8TE
XLR female 4x AES/EBU, S/PDIF Input
Variant: BNC 1 x 4TE
Variant: XLR 1 x 8TE
XLR male 4x AES/EBU, S/PDIF Output
Variant: BNC 1 x 4TE

Technical specifications


Audio data AES/EBU professional and consumer formats compliant with AES 3-1992r (1997), IEC 60958, EIAJCP-1201, and AES 11-1997
non-audio The card transparently passes non-audio data through.
Audio data 24-bit (with or without SRC)
Ancillary data Evaluation and transparent passthrough of AES/EBU ancillary data (CUVZ)

Audio data

Sample rates NEXUS system clock (44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz);2…192 kHz with sample-rate converter enabled
Latency 7/8 Samples (48/96 kHz); 1,2…2,4 ms (2 SRCs in chain)


  Sample-rate converters for each input and output
  Gain (mute…+20 dB) and phase inversion per input
  Gain (mute…+20 dB) per output


Diff. input sensitivity 150 mV (min.)
Impedance 110 ohm
Recommended cable length 100 m (max.)


Diff. output voltage 3,3 V
Impedance 110 ohm
Recommended cable length 100 m (max.)

Sample rate converter

  Separately available for each input and output port
Output frequency Synchronization of the out rate to the rate present at the input Free-running (controlled by internal quartz oscillator), 44.1/48 kHz, 88.2/96 kHz, 176.4/192 kHz
Distortion factor (THD+N) –130 dB (typ.), –115 dB (max.)
Latency 1.2 ms at 48 kHz (SRC output frequency)
0.6 ms at 96 kHz (SRC output frequency)
0.3 ms at 192 kHz (SRC output frequency)
Sample rates 30…200 kHz (32…192 kHz guaranteed)

Operation conditions

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

Storage conditions

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

Power supply

Voltage typ. +5 V
Currrent 220 mA, no active inputs/outputs
240 mA, at 48 kHz, 4 active AES inputs, SRCs off
400 mA, at 48 kHz, 4 active AES inputs, SRCs (In and Out) on
270 mA, at 96 kHz, 4 active AES inputs, SRCs off
440 mA, at 96 kHz, 4 active AES inputs, SRCs (In and Out) on
500 mA, at 192 kHz, 4 active AES inputs, SRCs (In and Out) on
20 mA, per active SRC

Mechanical data

Weight 0,25 kg
Note In the XLR version, the two front panels are connected with a ribbon cable.

NEXUS / NEXUS Star Technical specificationst




XETR Technical specificationst