Violectric DHA V590² Pro Headphone Amplifier, Preamp, and DAC - Manual (Page 16)

16
You can also use the remote control for this purpose.
Press the “ANA +/-“ buttons to change the analogue inputs.
Press the “DIG +/-“ buttons to change the digital inputs.
RESAMPLING
is a mighty feature for the transformation/restoration of jittered signals into high-quality signals. As
well, the signal quality of 44.1 or 48 kHz sources can be improved by converting them to a higher
rate. This also complies to the optical signals suffering from poor cables and USB signals which often
suffer from jitter caused by improper treated computer outputs. With the aid of the resampling
process nearly all jitter (and not only specific ones) is removed from the USB data stream without
using “asynchronous USB mode” which is nonetheless also a feature of the USB input.
This isn´t mystery at all, but a feature offered by so-called sample-rate converters - available since
the nineties of the past century.
While early sample rate converters with 20 Bit could provide conversion ratios of 1:2 to 2:1
(e.g. 44.1 to 88.2 kHz Sample-Rate) at 100dB dynamic range only, ratios of 1:48 to 48:1
(44.1 to 176.4 kHz = 1 : 4) with 32 Bit at nearly 180 dB dynamic range are feasible today.
In principle, the digital data stream is asynchronously disassembled by a DSP specially developed for
this purpose - and can be recombined at virtually any sample rate desired.
The quality of this recombination is directly dependent from the SRC´s clock source. Therefore,
inside DHA V590 a special low jitter oscillator is installed, the FEMTO-CLOCK, featuring a phase jitter
as low as 80 fs = Femtoseconds = 80x10
-15 .
The oscillator is powered by a low noise source made of discrete components.
By means of this process, all potential jitter vanishes almost completely and - due to the higher
sampling rate - the analogue filters after the converter stage can follow a much more straightforward
and "musical" design. Furthermore, all digital input signals will be completed to 32 Bit.
THE RESAMPLING BUTTON
By pressing the “RESAMPLING“ button, the modes OFF > x1 > x2 > x4 > BEST can be stepped
through in clockwise order.
- OFF, the white “OFF“ LED indicates that the resampling function is deactivated. The digital input
word (PCM and DSD) is forwarded to the D/A converter without alteration.
- x1, the white “x1“ LED indicates that the resampling function is activated. The digital input word will
be recombined and forwarded to the D/A converter at original sample rate.
DSD is transferred into PCM.
- x2, the white “x2“ LED indicates that the resampling function is activated. The digital input word
will be recombined and forwarded to the D/A converter at twice the original sample rate.
DSD is transferred into PCM.