Violectric DAC V800, Руководство пользователя

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resampling module generates auxiliary clock signals needed for further
processing of the digital signal within the unit.
After the resampling stage, an AES/EBU- (or S/P-DIF-) encoded PCM
signal is sent to the rear digital output, while the data contents and
auxiliary clocks are fed to the digital-to-analog converter.
The D/A converter comprises a digital filter, the volume control, the
stereophonic converter as such, as well as the analog output filters. It is
based on a delta-sigma architecture and provides a dynamic range of
127 dB and 64-...128-times oversampling.
The internal frequency of the digital signal (and potential interference
therein) is very high in comparison with the useful analog frequencies.
Therefore, the subsequent analog low-pass filters have to meet less
severe requirements in terms of high-frequency roll-off and can
therefore be realized as "musical", discrete two-pole filters.
Without careful consideration of the analog output stages it wouldn't
have been possible to make the outstanding performance of the top-
notch converter available at the analog outputs.
In case of the DAC V800, the converter is followed by an amplifier
specially designed for this purpose, with a topology similar to an
instrumentation amplifier.
It distinguishes itself by a wide dynamic range, minimum distortion and
high flexibility with regard to the achievable output level.
Within this amplifier, the output currents of the D/A converter are
transformed into voltages, while any interferences and processing
frequencies are completely removed.
Gain - i.e. output level – can be set by means of DIP switches over a
very wide range. Fine gain control is provided by trimmers. An error
amplifier caters for minimum DC offset.
Only now follows the output driver stage, feeding the output signal to the
corresponding terminals at extremely low impedance.
The balanced and unbalanced outputs can be used at the same time,
since they are buffered individually. Output impedance for all outputs is
significantly lower than 1 ohm.