I have to admit, when im listening to music, I rarely use the onboard sound on any motherboard, prefering to opt for a dedicated audiophile grade solution when possible.
Today we are using the Asus Xonar Essence STX sound card which is designed to fit into a PCI Express slot. The card is supplied in a rather fetching box with an oriental style image on the front, with the name of the product and the catchline, targeting the ‘audiophile’ audience.
The box is a stunning gatefold design which allows a customer to see the product behind the safety of a sealed plastic window. There are various specifications listed on either side.
The bundle is impressive, containing several adapters, cables, and literature on the product, including a detailed analysis manual.
The Essence is a strikingly designed product, with a grounded metal cover shielding the analog output circuitry. The anodised black shield has the same Chinese Tiger painted in gold on top and this acts as a Faraday shield, helping to prevent RF interference across the analog signal output.
The card has a variety of jacks, all of which are gold plated. There are right and left analog line outputs with a headphone output on a 6.35mm stereo phone jack.
Below that another stereo jack serves as both the line and microphone inputs and they are selectable via the Xonar Audio Center software.
At the bottom of the card is an RCA jack which offers a standard S/PDIF digital output capable of running at sample rates up to 192kHz. An optical S/PDIF driver is placed at the interior end of the port so that a Toslink cable can also be used with an adapter.
The card requires a molex connector to receive the necessary power. At the bottom of the PCB is the analog input circuitry which is based around a pair of R4580 low noise dual op amp chips, as well as a pair of 5532 dual op amps. This feeds into a Cirrus Logic CS5381, which is a 24 bit A/D converter chip capable of operating at sample rates up to 192kHz with a S/N ratio of 110dB. Asus have also focused on ‘Hyper Grounding’ which minimises the noise which can degrade the ultimate sound quality.
At the bottom right of the card are two LSI chips which handle all the audio data processing (they are branded with the ASUS name). The card can handle Dolby Digital decoding, Dolby Headphone and Dolby Virtual Speaker processing as well as Dolby Pro Logic II. There is also support for reverb and equaliser functionality in software.
Next to this is a power supply area which features multiple voltage regulator chips and a nice array of high grade Nichicon Fine Gold electrolytic capacitors as well as two purple Sanyo OsCon caps.
Asus are using the excellent Burr Brown PCM 1792 24 bit D/A converter – this sits to the left of the supply section and is adjacent to a vertical metal shielding strip. The headphone driver is a Texas Instruments TPA6120A2 chip which is a current feedback design capable of sourcing 80mWpc into 600 ohms with low levels of distortion.
The line level output stage is based around a pair of JRC 2114D dual op amp chips with a pairing of National LM 4562 dual op amps.