ASUS Announces Xonar Essence STX PCIe Audio Card

The Classics Deserve First-class Treatment

ASUS Announces Xonar Essence STX PCI-e Audio Card with 124dB SNR Audio and Built-in Headphone Amplifier for Extraordinary Audio Performance

Taipei, Taiwan, November 12, 2008
– Aimed as the culmination of searching for the very essence of sound, the new ASUS Xonar Essence STX range of audio cards delivers the purest, cleanest audio to offer users the ultimate audio experience ever from a sound card. Equipped with carefully-selected components, and ASUS’ exclusive Hyper-grounding and EMI Shield design, the Xonar Essence STX is capable of achieving an industry-leading 124dB SNR (Signal-to-Noise Ratio) in signal clarity. Furthermore, full-driving for any available headphone is provided through the built-in headphone amplifier—presenting unprecedented audio quality and under 0.001% of distortion to sate even the most demanding audiophile. Interestingly enough, the design for this audio card is based on a paradigm that is forty centuries old.

The Quest for True High-end Audio Starts Forty Centuries Ago

In China 4000 years ago, the ancient ancestors were also searching for instruments that were able to play "heavenly" music; not just to pay homage to the gods, but also to represent the harmony between man and nature. This process of seeking the most sublime and harmonious music between man and the environment resulted in the Tiger Chime, which not only represented the soul and quintessence of sound, but also served as the highest level of audio enjoyment. Like these ancestors, ASUS also searched for the best components and used only the finest designs to reproduce the purest of sounds. As a symbol of respect for these ancient pioneers, the Xonar Essence STX adopts a gold-plated Tiger Chime totem on the EMI shield—infusing a mix of ancient and cutting-edge technologies.

Industry-leading 124 dB SNR Delivers Pure Music for Listening Enjoyment
With the penultimate of component and design selection, the Xonar Essence STX is able to reproduce truly pure sounds, and delivers an industry-leading 124 dB SNR (Signal-to-Noise Ratio). This is 64 times clearer the most on-board audio solutions (85–88 SNR). It also features the ASUS exclusive Hyper-grounding circuitry design that utilizes a PCB design to separate signal and noise—ensuring that only the cleanest signals are passed on to ultra-sensitive components for decoding.

The Finest Component Selection to Deliver Crisp, Clear Audio
With a top-o-the-line Burr-Brown PCM 1792A Digital-to-Analog Convertor (DAC) to convert audio signals at 127dB signal-to-noise ratios, users will be able to enjoy minimum loss from the process of converting digital signals to analog sound. Additionally, Nichicon "Fine Gold" capacitors deliver rich bass and crystal-clear high frequencies (like the sounds from a piano or violin), allowing the Xonar Essence STX to achieve an amazing <10 Hz–90 kHz frequency response and 124dB dynamic range. Furthermore, The Xonar Essence STX’s EMI shield protects all analog outputs perfectly from any exterior electronic magnetic interference—resulting in the cleanest sound generation and delivery for the user´s enjoyment.

High Density Sound Performances with Built-in Headphone Amplifier
Most quality headphones usually require additional driving power; or else suffer from sounds that are dull and bland. The Xonar Essence STX is equipped with a built-in headphone amplifier capable of driving every available headphone with up to 600 ohms of impedance to their full extent and less than 0.001% of distortion—all without additional amplication. This ensures that only the most high density sounds can be heard from these headphones without the need to purchase an extra amplifier. Furthermore, the Xonar Essence STX also comes with the following features which include: Swappable OPamp sockets to help tune up unique sounds effortlessly, complete Dolby Home Theater technologies, and the latest DS3D GX2.5 3D gaming engine technology.


Audio Performance

Output Signal-to-Noise Ratio (A-Weighted):

- 124 dB for Front-out
- 110 dB for Headphone-out

Input Signal-to-Noise Ratio (A-Weighted):

118 dB

Output total harmonic distortion + Noise at 1 kHz
(-3 dB):

- 0.0003% (-110 dB) for Front-out
- 0.001% (-100 dB) for Headphone-out

Input total harmonic distortion + Noise at
1 kHz (-3 dB):

0.0002% (-113 dB) for Line-in

Frequency response (-3 dB, 24-bit / 96 kHz format):

<10 Hz to 90 KHz

Output/Input full-scale voltage

2 Vrms (5.65 Vp-p)

Headphone impedance

Optimized for 32–600Ω

Bus compatibility

PCI Express

Compatible with X1 to X16 PCI Express slots

Main Chipset

Audio Processor

ASUS AV100 High-Definition Sound Processor (Max. 192 KHz / 24bit)

24-bit D-A Converter of Digital Sources:

Texas Instruments PCM * 1 for Front-Out (127 dB SNR, Max.192 kHz / 24bit)

High Fidelity Headphone Amplifier

Instruments 2 * 1 (120 dB SNR, 100 dB THD+N @ Vcc±12 V, RL=600 Ω, f =1 kHz)

24-bit A-D Converter for Analog Inputs:

Cirrus-Logic CS5361 * 1 (114 dB SNR, Max. 192 kHz / 24bit)

Sample Rate and Resolution

Analog playback/ recording, sample sate and resolution

44.1K / 48K / 96K / 192 KHz @ 16/24bit

S/PDIF digital output

44.1K / 48K / 96K/ 192 KHz @ 16/24bit, Dolby Digital

I/O Ports

Analog output jack:

RCA jack * 2 (Front R / Front L)
6.30 mm jack * 1 (Headphone out)

Analog input jack:

6.30 mm jack * 1 (Shared by Line-In / Mic-In)

Digital S/PDIF output:

High-bandwidth Coaxial / TOS-Link combo port supports 192 KHz / 24bit

Other line-level analog input (for TV Tuner or CD-ROM):

Aux-In (4-pin header on the card)

Front panel:

Shared by Headphone out / 2 channels out /
Microphone in

Driver Features

Operating system

Windows Vista (32 / 64bit) / XP (32 / 64bit) / MCE2005

Dolby® technologies

Dolby® Digital Live / Dolby® Headphone / Dolby® Virtual Speaker / Dolby® Pro-Logic II

ASIO 2.0 driver support

Supports maximum 192 KHz @ 24bit with very low latency