The CS4397 is a complete high-performance 24-bit, 48/96/192 kHz stereo digital-to-analog (D/A) conversion system. The device includes a digital interpolation filter followed by an oversampled multi-bit Delta-Sigma modulator, which drives dynamic-element-matching (DEM) selection logic. The output from the DEM block controls the input to a multi-element switched-capacitor D/A converter/low-pass filter with fully differential outputs.
This multi-bit architecture features significantly lower out-of-band noise and jitter sensitivity than traditional 1-bit designs. The advanced DEM guarantees low noise and distortion at all signal levels.
The CS4397 features multi-standard support for PCM (pulse code modulation), Direct Stream Digital (DSD), and external interpolation filters.

•24-bit conversion
•Up to 192 kHz sample rates
•120 dB dynamic range
•-100 dB THD+N
•Supports PCM, DSD, and external interpolation filters
•Second-order dynamic-element-matching (DEM)
•Low clock-jitter sensitivity
•Digital de-emphasis for 32 kHz, 44.1 kHz, and 48 kHz
•External reference input
•Package: 28-pin SOIC; option for lead-free assembly
 

Need more info about the sound and modification like here also? Check this website-->

http://lampizator.eu/LAMPIZATOR/LAMPUCERA/CD%20DAC%20Lampucera%20lampizator.html

Need more info about this Aikido 6DJ8 Headphone tube amp?

http://www.tubecad.com/2006/04/blog0062.htm

Thanks to Lampizator & DHTrob

Components in the modification where desolderd from a Harman Kardon HDCD CD-player. Since it's all Sanyo inside :)