Do you remember there is a “**Special Method**” file? This file is created by our PC iTunes real time playback CD via Weiss AFI1 firewire interface -> AES digital output to our Crookwood mastering console -> loop back to Lynx AES16 digital audio soundcard -> capture input by WaveLab software. This test checks a lot of things.- Is iTunes8 live CD playback bit identical data?
- Is Weiss AFI1 output bit identical data?
- Is Crookwood mastering console completely transparent (when no processing is insert)?
- Is Lynx AES16 soundcard capture bit identical data?
- Is WaveLab record bit identical data?
If just one tiny section (be specific, 1 sample error), the whole signal path is broken (Remember 1 second music carries 88200 stereo samples, each with 16bit word length. A lot of data is passing through this loop), the Wavelab captured file will be different than the original source file.The above photo shows the “loop captured” file play together with the WaveLab Ultra Safe ripped CD file. Bit transparent result again. Well, we of course very happy that our digital chain is clean.In this CAS series, we keep on talking an important issue – digital data can be compare, clone and verify. In the file comparison tests, we prove iTunes 8 and up to date computer/CD/DVD drives, are capable to rip bit perfect data same as EAC, Wavelab and Plextools. Moreover, iTunes can output bit transparent digital data as well. I will suggest audiophile make good use of iTunes. It has a lot of good feature, the album management alone is way above all other programs.国外某大烧无聊，用苹果机上的itunes8实时播放CD盘片，然后实时通过过线链接Weiss某外部界面，再实时连接到Crookwood某中控台，再实时通过Lynx AES16e专业界面卡录会电脑内，实时用专业录音软件录为WAV文件。
比较WAV文件和CD盘片，结果还是bit perfect. 这个试验很简单明了地证明了通过电脑可以发烧，哪怕只是使用普通光驱和普通软件。
对于正常发烧友而言，唯一要注意的就是外置DAC了，什么jitter之类的都可以靠DAC来解决。至于价格，你愿意投资多少就能够回报给你多少声音，不过有一点事肯定的，同价位DAC不会比同价位CD机差。原因有2：
1，CD机的转盘部分和控制部分需要花费大量的成本。
2，前文已经说过，PC出来的信号，是很容易接近完美的。
当然了，如果你接一两千元的DAC，那么确实不要指望能够获得坛子上大烧们高价CD机的效果。
欢迎热烈友好讨论。
