ASUS Essence STX II PCI Express Sound Card

ASUS Essence STX II PCI Express Sound Card

ASUS Essence STX II PCI Express Sound Card


Product Highlights

  • 124dB SNR Audio Quality
  • 120dB SNR Headphone Output
  • Low Jitter with TCXO clock source
  • LDO Regulators and WIMA Capacitors
  • 600 Ohms Headphone Impedance
  • Additional Gain for In-Ear Monitors
  • Op-amp Swap Kit
  • Dolby Home Theatre Surround
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  • 1Description

The Essence STX II PCI Express Sound Card from ASUS is a PCI Express sound card that is optimized for use with headphones. It features 124dB SNR (signal-to-noise ratio) audio clarity with headphone output that reaches 120dB SNR using the multichannel daughterboard that slides into a slot adjacent to the Essence STX II.

This card is built using a temperature-compensated crystal oscillator (TCXO) clock source whose accurate timing technology helps to ensure low jitter. The Essence STX II also uses a dedicated four pin Molex power connection instead of drawing power directly from the PCI expansion slot which equates to a cleaner supply of electricity. High-fidelity low-dropout (LDO) regulators further assist with power optimization and WIMA capacitors also help to deliver balanced sound.

The built-in headphone amplifier supports up to 600 ohms impedance and an additional gain control designed for high-sensitivity IEM headphones allows musicians and audio purists to use earpieces that channel audio straight to the ear canal, allowing ambient noise to be isolated.

In addition to its use with headphones, the Essence STX II may also be used with your Windows-compatible system to create surround sound environments using Dolby Digital Live, Dolby Pro Logic II, and Dolby Virtual Speaker.

Adjust the Sound for Your Ears
The Essence STX II benefits from swappable op-amp sockets that allow users to create different timbres and tonal combinations.
Additional Op-amp Swap Kit
The Essence STX II comes with a swap kit that includes three additional op-amps - two Texas Instruments LME49720s and one MUSES 8820 - and a clamp tool that helps make it easy to remove the op-amp microchips
Dolby Surround Sound
The Essence STX II benefits from Dolby Home Theater technologies that can help turn your PC into a true home-theater system.

Dolby Digital Live
Reproduces Dolby Digital 5.1-channel surround sound, immersing players in entertainment experiences with high-quality surround that puts you at the center of the action

Dolby Pro Logic II
Transforms stereo sound into 5.1-channel surround that changes audio perception

Dolby Virtual Speaker
Reshapes two-channel and 5.1-channel stereo content into virtual surround sound even with just two speakers, reproducing the environment of a 5.1-speaker home theater system

Dolby Headphone
Simulates surround for personal audio by using digital signal processing. It delivers up to 7.1-channel surround over any headphones for more vibrant and spacious listening
MUSES op-amps
The musicality that Essence listeners expect is encapsulated by MUSES 8920 and MUSES 8820 op-amps, which deliver true-to-life tonality and spacious sound imaging
In the Box
ASUS Essence STX II PCI Express Sound Card
  • Op-amp Swap Kit
  • 3.5mm-to-RCA Cable
  • 6.3-to-3.5mm Adapter
  • S/PDIF Adapter
  • Driver CD
  • Limited 3-Year Warranty
  • Table of Contents
    • 1Description


    Audio Interface PCI Express
    Audio Performance Output Signal-to-Noise Ratio (A-Weighted) (Front-out):
    124 dB

    Output Signal-to-Noise Ratio (A-Weighted) (Headphone-out):
    120 dB

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

    Output THD+N at 1 kHz (Front-out):
    > 0.0003% (-110 dB)

    Output THD+N at 1 kHz (Headphone-out):
    > 0.001% (-100 dB)

    Frequency Response (-3dB, 16bit/44.1 kHz input):
    10 Hz to 90 kHz

    Output/Input Full-Scale Voltage:
    Line output (RCA, 3.5) : 2 Vrms (5.65 Vp-p)
    Headphone output : 7 Vrms ( Vp-p)
    Chipset Audio Processor
    ASUS AV100 High-Definition Sound Processor (Max. 192 kHz/24-bit)
    Digital-to-Analog Converter (DAC) TI Bur-Brown PCM1792A
    Sample Rate and Resolution Analog Playback Sample Rate and Resolution:
    44.1, 48, 96, and 192 kHz @ 16 & 24-bit

    Analog Recording Sample Rate and Resolution:
    44.1, 48, 96, 192 kHz @ 16 & 24-bit

    S/PDIF Digital Output:
    44.1, 48, 96, and 192 kHz @ 16 & 24-bit

    ASIO Driver Support:
    44.1, 48,88.2, 96, 176.4, 192 kHz @ 16 & 24-bit
    Connectivity Analog Output
    1 x 6.3 mm jack (1/4") Headphone out
    2 x RCA (unbalanced)

    Analog Input
    1 x 6.3 mm jack (1/4") (Line-in/ Mic-in combo)

    1 x S/PDIF out (1 x Coaxial)
    1 x Front-Panel Header
    Special Features Dolby Technologies: Dolby Digital Live / Dolby Headphone / Dolby Virtual Speaker / Dolby Pro-Logic II
    Operating System Windows 32 & 64-bit: 8.1, 8, 7, and XP
    Dimensions 6.61 x 4.21" / 168.00 x 107.00 mm
    Weight Not specified by manufacturer
    Packaging Infodefwvtywzbcddtsewqtcebvcwv
    Package Weight 1.7 lb
    Box Dimensions (LxWxH) 11.4 x 9.3 x 3.2"


    Essence STX II PCI Express Sound Card is rated 4.1 out of 5 by 10.
    Rated 5 out of 5 by from As best as music gets on PC For all of the individuals who say that the card is laid back or does not perform as expected - I would like to hear what output are you using that leads you to such comments. If you are using some headphones that came free with your phone or expect Beats by Dre to give you some phenomenal results, you are greatly mistaken. The card has a phenomenal potential when combined with the proper headphone. However, I must note that one absolutely NEEDS to adjust the mixer to specific taste - otherwise, the card does sound dry when you hook it up right out of the box. I tweaked it to my taste and use Sennheiser HD650 - could not be happier with the result coming from a computer. Tune it up correctly and you will find to have crystal clear, yet aggressive sound pleasuring your ears.
    Date published: 2015-03-30
    Rated 3 out of 5 by from Review I use this mainly as headphone amplifier/DAC. Pro: It has its own Molex power connection. Some may dislike this as it adds an additional item for cable management. But I think it's great. It will prevent problems related to motherboard's pcie slot not supplying enough power. I used to have the Sound Blaster ZXR card and its power dependency on the pcie slot regularly lead to the card's driver to crash. This independent power supply make this a great DAC if you're going to upgrade to an external amp. Con: The card sounds a bit too laid back for my taste. You probably have to change its op-amp to get a better feel.
    Date published: 2015-03-13
    Rated 5 out of 5 by from ASUS Essence STX II PCI Express The best audio card for music lover, Be sure disable your onboard sound card before installation. I'm listening it with my Sennheiser HD 598, produce amazing sound, particularly the software affords you so many options to color your sound. For those who loved singing Karaoke on the computer, this sound card is the best. Thanks BH Photo Video for very fast transport. You guys have always been my first stop shop for nearly everything. I definitely highly recommended this sound card to anyone from whether you are an amateurish or professional .
    Date published: 2015-12-10
    Rated 5 out of 5 by from Essence STX II PCI Express Awesome sound card Replaces Creative XFI Elite series card which at the time of purchase was just about as good as it got for sound cards. The Essence II does not Blow away the old XFI but it does definetly sound cleaner with a better low end. The build quality of the Essence II is excellent high quality components are used through out the card. If you want the best sound you can get out of an add on card then get this card!
    Date published: 2015-03-02
    Rated 5 out of 5 by from GREAT!!! Soundcard The first to actually get me this soundcard. Everything I expected!!!! Yee-Haw!
    Date published: 2015-04-12
    Rated 5 out of 5 by from Essence STX II PCI Express Sound Card by ASUS Recording vinyl to 24 bit digital format. This card is extremely quiet and captures more detail than previous 24 bit sound cards.
    Date published: 2016-04-15
    Rated 4 out of 5 by from Hard to Justify the Cost This is a great card with excellent sound quality, however, I can't really discern any difference between this and my Xonar DX/Soundblaster Z using the JBL LSR305 studio monitors with this card.I'm satisfied with my purchase knowing I have the best internal sound card on the planet, at least that's my psychological justification for purchasing two of these anyway, but honestly, aside from being a bit louder there is practically no difference (with HF turned on all cards). Some people say the muses amps that came with the card are junk and recommend throwing in 3 MUSES 02 op amps, but at $+ for those op amps you might as well save the $+ you'll be paying for your next set of speakers (I'm looking at KEF LS50s personally).Aside from performance, I really am disappointed in ASUS on the software side of things. The Essence Audio center is literally a re-skin, actually no, not even a re-skin of the software suite from a few years back. All you get is a change of color. I don't like owning a $+ sound card with an ugly & outdated software package. What a mismatch.
    Date published: 2015-05-13
    Rated 5 out of 5 by from Excellent sound card Easy installattion, superb sound quality.
    Date published: 2014-12-12
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