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WHITE PAPER
USB DAC GUIDE TO COMPUTER-AUDIO | 12.2015 | 4
USB-B CONNECTION IN DETAIL
High End audio DAC mode through USB-B port.
First of all this port is using the most advanced technologies to get the best sound
from your audio files. There is no limitation by the audio DAC, as it handles 2ch
PCM and DSD provided by the PC / Mac. You can enjoy any file stored on your
computer and which can be played back by the media player on the computer.
The signal will be outputted via the USB-A connection on the computer and send
to the USB-B port of the DAC.
The USB cable needs to be
a USB-A to USB-B type one.
A quick overview of the USB-B possibilities:
1st It will bypass the audio board of your PC / Mac in order to avoid all digital
noise from your PC / Mac.
2nd It will also be able to bypass the audio mixer in your computer which is a
source for distortion.
The mixer is the DSP of the PC where all sound from any software will be mixed
together and sent to the speakers, but in order to achieve this mixing the DSP
has to convert all dierent formats coming from dierent software. This this will
heavily modify the audio file and lower the sound quality. When we bypass the
audio mixer, the original audio file will be outputted bit-perfect – no modification
to original signal happens.
3rd The asynchronous mode will give control over the timing of audio data trans-
mission to the receiver side (USB-DAC), thereby minimizing jitter for best audio
performance.
4th It’s compatible with all file formats including DSD via DoP (All the formats that
your computer software player can read). This diers by USB-DAC specification.
SYSTEM REQUIREMENTS
In order to enjoy the best sound we will now explain how to make it happen.
List of equipment
Audio Files, Computer, Media Player on PC, USB-DAC cable,
Driver for USB-B DAC, USB-B DAC
PC / Mac A Player JRiver A good USB-A
or Audirvana to USB-B Cable
USB / DAC Driver for PC USB / DAC
The music files
First we need high end audio files like Flac HD and DSF (DSD). In case you don’t
have any yet you can work with standard files too. It is not just limited to FLAC HD
or DSF as we explained before. All formats can be played. However for the best
quality you can get high definition files downloaded from the internet. At the end
of the document we will list some web sites oering such high end audio tracks.
Then we need a so called bit-perfect player
A common thinking is that digital is equal to digital, however this is only the case
if the data in the received file is “bit-perfect” to the playback file. However, this
often isn’t the case if you are using a computer as a source. In a computer the
data signal has to pass many stages of input and output before the signal will be
outputted via the USB connection to the USB-DAC.
First, the computer will use the on board DAC (Digital Audio Converter). All
computers have an internal DAC, generally of poor quality, simply because the
primary purpose of such a machine does not oer any guarantee in terms of
quality sound reproduction. This is why music lovers often use an external DAC.
However it is not all about an external DAC.
The OS “operating system” running on the computer itself contains a set of
functions responsible for processing audio streams more or less “neutral”,
ideally without altering them. This software layer should not interfere with the
characteristics of the signal, but in practice this is not the case, so one source
of distortion.