ASUS Xonar DX 7.1 PCI-E Sound Card Review

Electronics Overview

Front channel DAC-CS4398



This Cirrus Logic Digital to Analog Converter (DAC) offers advanced ∆∑ (Delta Sigma) architecture, a 120 dB Dynamic range and -107dB THD+N%. This unit also offer low jitter sensitivity and differential stereo analog outputs. According to the specifications this is a high quality part and a very good choice by the Xonar designers. This unit would usually be seen in high end DVD players and home theatre audio video receivers and ensures the front channel opamp is receiving crisp, clear audio for amplification and signal conditioning to line-level for output to your speakers or receiver unit.





This Digital to Analog Converter (DAC) offers 24/192 kHz operation with a dynamic range of 114dB and a THD+N% of -100dB. This DAC system also offers digital interpolation, de-emphasis filtering and volume control with soft ramp of 1db graduations. This is a 6 channel output unit that powers the remaining channels of the Xonar DX card.

While this DAC doesn’t have the specifications of its bigger brother on the front channels, it is still a very reasonable unit to put on an audio device at this price point as it offers great dynamic range and reasonable THD+N numbers.





The Analog to Digital Converter (ADC) used on the Xonar DX has a dynamic range of 114dB and a THD+N% of -105dB. This unit will provide quality sound recording capabilities to this card considering the price point. This chip will also convert analog signal inputs from the AUX input, Line input and Microphone inputs. The use of a decent ADC further promotes this card's use in a HTPC role offering clean and clear connections from other audio/video devices such as external CD players and other devices.




This opamp seems to be a mainstay in consumer audio design and is now considered a rather generic unit. Believe it or not, this opamp has been seen on audio products from almost every manufacturer as they are rather easy to fit into a design and would be cost effective for mass production. The 4580 series are a cheaper priced unit that will do the job but again, the price point of the card would influence such design decisions.





The 5532 is a bi-polar opamp with wide scale usage in consumer level electronics. The specifications on this device are reasonable but again there are better chip amplifiers out there. That being said, this chip has gained extremely wide scale acceptance because of its performance to price ratio since it can give decent performance over similarly priced opamps. The 5532 is considered a “workhorse” a chip that designers fall back on when needing an audio opamp.


PCI-E to PCI Bridge Chip PEX8111


This chip is what gives us one of the best hardware features on the DX: its PCI-E compatibility. Finally we have a card that can use the small PCI-Express X1 connectors. The PEX8111 chipset is a bridging chip that allows designers to connect PCI designed cards and chipsets to the newer PCI Express interface bus.

The bridge chip is acting in a forward bridge capacity on this card since this chip allows the PCI card to connect to a PCI-E connector or in reverse bridging mode allow PCI-E card to connect to a PCI interface.