ASUS XONAR Essence STX PCIe Audio Card

Introduction and Specifications

Placing a product in the "audiophile" category automatically opens it up for scrutiny of the highest order. The new Asus Xonar Essence STX "headphone amp card for audiophiles" is Asus' latest in a line of audio card offerings that pretty much cover the spectrum of PC audio applications. Asus now offers audio cards designed for gaming to Home Theater PC applications. We recently gave you a thorough look at the ASUS Xonar DX PCI Express 7.1 Audio card . And today we're looking at the latest iteration of the product, targeted at those of us with a more discerning ear.

The Xonar Essence STX audio card boasts a host of features that are clearly aimed at end users wanting the best possible listening experience their PC can offer. In this HotHardware evaluation, we are going to explore this card's features and performance with particular emphasis paid to sound quality.

ASUS Xonar Essence STX
Specifications and Features
Output Signal-to-Noise Ratio (A-Weighted):
124dB for Front-out,117dB for Headphone-out (600ohms) dB

Output THD+N at 1kHz:
0.0003% (-110dB) for Front-out, 0.001% (-100dB) for Headphone-out
Frequency Response (-3dB, 24-bit/192kHz input):
<10Hz to 90KHz

Bus Compatibility
PCI Express:
-PCI Express Rev. specification compatible
-Compatible with X1, X4, X8, X16 PCI Express slots

Main Chipset
Audio Processor:
ASUS AV100 High-Definition Sound Processor (Max. 192KHz/24bit)
24-bit A-D Converter for Analog Inputs:
Cirrus-Logic CS5381* 1 (120dB SNR, Max. 192kHz/24bit)

Sample Rate and Resolution
Analog Playback Sample Rate and Resolution:
44.1K/48K/96K/192KHz @ 16/24bit
S/PDIF Digital Output:
44.1K/48K/96K/192KHz @ 16/24bit, Dolby Digital

I/O Ports

Analog Output Jack:
RCA jack *2 (Front R / Front L), 6.30mm jack*1 (Headphone out)
Other line-level analog input (for CD-IN/TV Tuner):
Aux-In (4-pin header on the card)
Front-Panel Header:
Shared by Headphone out / 2 channels out /
Microphone in S/PDIF Header: Connects to compatiable graphic cards for HDMI output

Input Signal-to-Noise Ratio (A-Weighted):
118 dB
Input THD+N at 1kHz:
0.0002% (-113dB) for Line-in
Output/Input Full-Scale Voltage
2 Vrms (5.65 Vp-p)

24-bit D-A Converter of Digital Sources:
Texas Instruments PCM1792A*1 for Front-Out (127dB SNR, Max. 192kHz/24bit)
High Fidelity Headphone Amplifier:
Texas Instruments 6120A2*1 (120dB SNR, 100dB THD+N @ Vcc±12V, RL=600?, f=1kHz)
Analog Recording Sample Rate and Resolution:
44.1K/48K/96K/192KHz @ 16/24bit
ASIO 2.0 Driver Support:
Supports 44.1K/48K/96K/192KHz @16/24bit with very low latency

Analog Input Jack:
6.30mm jack *1 (Shared by Line-In/Mic-In)
Digital S/PDIF Output:
High-bandwidth Coaxial/TOS-Link combo port supports 192KHz/24bit
Operating Systems
Windows Vista/XP(32/64bit)/MCE2005

Dolby Technologies:
Dolby® Digital Live
Dolby® Headphone
Dolby® Virtual Speaker
Dolby® Pro-Logic II

Smart Volume Normalizer Xear 3D Virtual Speaker Shifter:
Normalizes the volume of all audio sources into a constant level and also enhances your 3D sound listening range and advantages in gaming Virtual 7.1 speaker positioning

Magic Voice
Xonar Essence STX provides VocalFX, the latest vocal effect technologies for gaming and VoIP, including: -VoiceEX: produces vivid environmental reverberation for your voice in EAX games -ChatEX: emulates different background environment effects when you chat online -Magic Voice: changes your voice pitch to different types (Monster/Cartoon…) for disguising your real voice or just for fun in online chatting.

Karaoke Functions FlexBass
Music Key-Shifting and Microphone Echo effects like professional Karaoke machine Professional Bass Management/Enhancement system

3D Sound Engines/APIs
Vista: DirectSound3D® GX 2.5, DirectSound® HW, DirectSound SW, A3D®1.0, OpenAL generic modes, 128 3D sounds processing capability XP: DirectSound2.5 SW, A3D®1.0, OpenAL generic modes, 128 3D sounds processing capability

The Xonar Essence STX comes nicely packaged in a display box with "124 dB SNR / Headphone Amp Card for Audiophiles" proclaimed on the front and containing one each of the following:
  • Xonar Essence STX 2 Channel PCI Express Audio Card
  • RCA to 3.5mm Y cable
  • 6.3mm to 3.5mm adapter
  • S/PDIF TOSLINK optical adapter
  • Driver CD
  • Quick Start Guide
  • Audio Precision test report

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