CEN.GRAND 9i-92SA III DAC/HEADPHONE AMP/PRE AMP

9i-92SA III "Golden Thrush" DAC / headphone amplifier / preamplifier is a desktop hifi product for headphone user.  A variety of advanced technologies and solutions such as USB isolation technology were integrated , such as ESS 9038Pro  DAC chip work in eight channel parallel connection, etc..   The audio quality especially headphone amplifier performance is excellent.  It will get good effect in driving the mainstream headphones such as HD800S and T1-II.

"Golden Thrush"  has many functions and performs well on the adaptability of the headphones.  There are not only four types of output mode for adapting many kinds of headphones but also different output circuits for high and low impedance headphones.  As a headphone hifi product, "Golden Thrush" is good at both performance and function.
The 9i-92SA "Golden Thrush" consists of the following parts:
1: USB interface.  XMOS second generation XU208 + FPGA digital processing module ,  isolation technology is used to isolate noise from the computer.  Support for NativeDSD512  and PCM384 input.
2: AK4118+ dual ESS 9038Pro DAC chip.  The SPDIF receiver has three interfaces: coaxial, optical, and AES, support  PCM 24bit/192KHz and DOP (DSD64) inputs.
3: Headphone amplifier.   It has 6.35 unbalanced interface and 4-pin XLR balanced interface.  It has four output mode: Normal, BTL, Active Ground and Parallel.
4: Pre-Amp consisting of discrete components.  "Golden Thrush" can be used as a pre-amp, the input interface is RCA and XLR,  with infrared remote control.
5: Power supply and display system.
 
Two ESS 9038Pro DAC chip are used and one for each channel.  There are 8 internal DAC in each 9038Pro chip.  Most of DAC which used 9038Pro chip only use one or two of them.  The others are idle.  The mode of multiple DAC channel parallel has many advantages but it is not easy to get good sound and  heating is serious.  The 9i-92SA III is different.  With careful design and adjustment,  the structure of 8 internal DAC parallel is one of important reason of good sound.
There are 4 modes of connecting to headphone . Each mode has its own characteristics,  and the difference is very obvious.  This funtion is very useful for user , because he can chooses the most suitable mode for his headphone.  Under normal conditions high-impedance and high-quality headphones are suitable for Blanced(BTL) mode,  in this mode the headphones can fully be driven by Amp.  When your headphones  are easier to be driven , you can choose parallel or Active G mode to drive them, as well as Normal mode.  Here,  I would like to introduce what is the "virtual ground(Active G)" mode.
Usually the positive terminal of the headphone cable should be connected to the positive output, and the negative terminal should be connected to the GND.  If we make the input terminal of  amplifier to GND, its output will get 0 level, which is the same level as GND.   At this time if the negative terminal of the headphone is connected to this 0 level , it is equal to connecte GND.  But this is not the real GND, only simulated GND,   that is to say "virtual GND"(Active Gnd).   This kind of connection can get a more unique sound,  the listening experience is warmer and softer, more suitable for listening to human voice or string.   In short,  the "virtual GND"(Active G) mode provides users with an effective tuning method that increases adaptability and entertainment.
The second generation of XMOS is the latest XMOS solution which is faster than last.  Isolation technology enables blocking between the computer and 9i-92SA.  The ground wire is not connected so noise was almost completely isolating from the computer.  This feature is very effective because there are a large number of switching power supplies inside the computer that generate a lot of noise which can interfere with the analog circuit ,  audio performance will be degrade.  Isolating these noises can significantly improve the purity of the sound.