The XAF board provides 8 inputs
and 8 outputs for the ADAT 8-channel format used, for example, by digital tape
machines.
The inputs and outputs of the board can optionally be equipped with sample-rate
converters and can therefore handle asynchronous signals. All converters can be disabled
together using the control program.
The DSP is a standard feature allowing for audio corrections with high quality. For
example, the input level can be adapted to the required recorder headroom,
and phase inversion allows »reverse-polarity« signals already at
the inputs of the audio network to be corrected.
The
ADAT format utilizes an easy-to-use optical format. The signals
are transmitted using two TosLink ports.
Synchronisation
Sample-rate converters for connecting asynchronous signals can be
incorporated on request. Audio with rates between 40 and 50 kHz
can be applied.
In addition, the board includes a quartz-controlled generator producing
a 44.1-kHz or 48-kHz wordclock. Accuracy is better than 50 ppm.
Separate Synchronisation
The output signal can be synchronised to the input signal of the
board as required independently of the system clock. The necessary sample-rate converters
also make the signal available on the NEXUS audio network.
Noise Shaping and Dithering
The XAF board allows for outputting the 24-bit NEXUS audio signal
to external downstream units with a 16-bit or 20-bit resolution. Inaccuracies
emerging from truncation errors leading to deterioration of the S/N ratio and THD&N
are minimized by re-quantizing using a dithering algorithm. In addition,
a selectively engaged noise-shaping function moves the noise energy up to frequency
ranges less perceivable to the human ear.
The noise reduction achieved in the range below 1 kHz is approximately
15 dB and about 10 dB in the critical range around 3 kHz. Noise shaping
is computed on the integrated signal processor on the basis of a 5th-order algorithm.
Indicators
The front panel of the board includes an LED indicating the status
of the input signal.
|