Auzentech X-Fi Prelude 7.1

Jake Carrol puts Auzentech’s latest through its paces, and finds some interesting results.

Product differentiation is critical in the soundcard market. The Auzen Prelude 7.1 is indeed different. The card uses a Creative CA20K X-Fi SPU but everything else is modified, including high end Asahi-Kasei AK-5394/5396 series ADC/DAC converters used for 24bit I/O. These ADC/DAC units are much more robust than the standard Creative fare.

The overall package is different too, with only the PCI card found in the box. You won’t find any accessories such as cables or ‘linky bits’. Another interesting differentiator is the savagely bright LED beaming from the back of the SPDIF link. While having an active function, it also looks impressive, for those that care for aesthetics in PCI devices. Then there is the inclusion of swappable OPAMP’s (Operational Amplifiers) from Texas Instruments. The idea here is that users can upgrade to higher quality OPAMP’s to attain a more refined signal or a specific sound. For example, the OPA-627AU component offers a warm, rounded sound, whereas the OPA-637AU is more suited to high resolution, high dynamic range music. Consider it overclocking for audiophiles.

Testing the Auzen X-Fi
We employed RightMark’s Audio Analyser for metric generation. For qualitative testing, we used a 3m square carpeted room and 16bit, 24bit and 32bit audio content:
• 16bit, 44.1kHz: Cog ‘The New Normal’ [CD Audio]
• 24bit, 96kHz: Columbia Pictures ‘Hellboy’ Blu-Ray DVD [BD PCM Audio]
• 32bit, 192kHz: Biped Productions ‘Gust of Gravity, In Superposition’ [ProTools Audio]

We used two sets of enclosures:

• Altec Lansing 621’s
• Tanoy Reveal 6D monitors

We deliberately took a set of medium to high end computer speakers and a set of studio reference monitors here, as a means to highlight performance in a range of environments.

Quantitative Analysis
We were slightly concerned by the THD and Dynamic Range figures produced at 16bit output resolution, with 0.095 percent THD. Figure 1.0 shows the comparison between 16bit, 24bit and 32bit THD.

This suggests Auzentech has geared the card for 24bit playback performance, as a preemptive move for the next consumer generation of audio.




Qualitative testing
We sat down to try and appreciate a difference. if any. from Auzentech. Listening to our CD and BD audio, it was instantly obvious that ‘more’ could be heard. The decay of cymbals, the fret-buzz of guitars and the luscious bass undertones jumped out at us. Low frequency effects and subtle dynamics (such as actors breathing) were obvious and transparent. At 192kHz, the Auzen amazed us. The negative aspect of the 192kHz audio, however, was that it was very hard to appreciate on anything but the reference monitors from Tanoy. It is important to note that the board doesn’t actually support native 32bit output, but rather 32bit internal processing (IEEE Float) downsampled to 24bit for the analogue output path.

Like so many complex PCI devices of this nature, the Auzen had installation problems. Crackling and PCI bus ‘pops’ were apparent on two different motherboards until we switched PCI slots. Current conjecture on many audio forums suggests that, just like some Creative products, the Auzen doesn’t play well with others (IRQ’s).

The Auzen X-Fi Prelude 7.1 is a card for lovers of serious audio. With more ADC/DAC clout than any Creative card, upgradeable components, impressive driver support and a THD rating that Creative cannot touch, we consider this a stand out product.