About external USB DAC
A higher dimensions music!
Impressions of a guy upgrading his PC rig
PC > PC sound card Creative XFI Xtreme Music (i.e. not a stock PC card!) > headphone Audio-Technica ATH-AD700
PC > USB DAC/amp FiiO E17 > headphone Audio- Technica ATH-AD700:
"Anyway, I got on to a lot of forums and found HeadFi (Yes, say goodbye to your wallet!). Never fully understood the world of Dac's and Amp's I started my research!
I searched the forum's and felt there was a few people in the same position as me who were feeling unsure about an alternative to PC sound card's, so I decide to the plunge!
Yes I could have grabbed an Asus ST/STX or Creative Tit HD but I wanted to go a different direction, so I went with the Fiio E17.
Conclusion: Done the whole unboxing and setup that everyone has probably seen, plugged her in to the computer and ran it through her paces!
I listen to various music from Classical, Rock, Pop, electronic, using mainly FLAC files.
Sound quality compared to the Xtreme Music was overall a big improvement!
The sound was full and warm! I immediately felt like I was listening to (what I describe as) a high end Hifi system!
It's very reassuring as I come from a Creative product to something totally different as in the Fiio and be in awe about what I'm hearing.
The Fiio sounds like a professional athlete compared to say an amateur running a marathon, well paced full of energy and doing what it loves doing, where as the Creative was more like a weekend warrior!"
About digital audio
A digital audio system is composed of:
. A storage module: Music is stored in file as a series of bits 0 & 1 with different encoding formats (MP3, WAV, FLAC…).
. A player: The player decodes the bits 0 & 1 to PCM digital audio signals.
. A DAC (Digital to Analog Converter): The DAC converts the PCM digital audio signals to the original analog audio signals.
. An amplifier: The amplifier amplifies the analog audio signals.
. A speaker: The speaker restitutes the music.
Like a PC or a Mac, an Android device is a digital audio system.
An Android device running on a kernel with a USB audio driver, like a PC or a Mac, can output the PCM digital audio stream to an external standard USB DAC & amplifier & headphone, much more efficient than the internal DAC & amplifier & speakerphone.
extracted from the official request to Google for enabling USB audio: