The Auzen X-Fi Prelude

I'm a terrible engineering student. I can't tell a Chebby filter from a Butter filter even if my life counted on it, but I can generally tell if a board is well-designed or not. My initial impressions of the board were good. Output signal traces did not intersect, so I assume channel isolation would be good, with reduced coupling. Conclusion? Good board design!

As you can see, the output section is divided into functional blocks (see the repeating pattern in component placement). The placement symmetry should in theory reduce noise and distortion levels.

This is a marked contrast from my Creative Audigy 2 ZS card where the output blocks number 2 and 3 are actually placed quite close to each other. On the Auzentech card, the signal has a free flowing path from the chip to the DAC, and from the DAC to the buffer amps and then to the outputs unimpeded. Very good.

The opamps for each of output were also given ample rail capacitance to smooth out any power supply sags, surges and ripples. This is something the Audigy 2 didn't do much about. Expect better sound quality. I can't tell if they decoupled the V+ to VGND, but I'm betting they did.

The board also comes with the much touted X-RAM, 64 MB of it. In truth, X-RAM is nothing more than a marketing moniker for onboard memory, in this case, two 32 MB PC-133 SDRAM chips made by Micron Technologies. There's nothing new about adding RAM on the sound card, of course. Creative claims it will help reduce CPU usage in games that support it, but that will only happen in the future, if at all. At least, I don't have to get a Creative X-Fi Fatal1ty with Wendel's smug face all over the box!

Micron SDRAM Chips

The OpAmps

Although Auzentech didn't go all out like they did in with the Meridian, they did allow for one socketed operational amplifier (opamp), which is better than nothing. I love rolling opamps. From the specs flying around, the amp runs on 8V although they didn't tell if it was dual or single. Assuming it's dual, you could probably slap in an OPA2107, a browndog adapter with dual AD774, depending on your taste. You can replace it with almost any other dual opamp for that matter. If you can buy the right chip, pry the old one out of its socket, you're probably qualified.

The Auzen X-Fi Prelude 7.1 sound card also comes with a Xilinx Field Programmable Gate Array (FPGA). Although this isn't a SPARTAN or one of the larger FPGAs, I'm betting that it's there to allow functionality and support for Creative drive bay controllers.

Xilinx FPGA

Power Regulators

Lastly, this sound card's power delivery system is a bit more complex than your average sound card. It has its own inductor to smooth out the current flow, a rarity for a sound card although I've seen the topology on the much more expensive Creative Sound Blaster X-Fi Elite Pro sound card. Its pre- and post-regulation ripple reduction capacitors also provide a considerably higher amount of capacitance than those on my Creative Sound Blaster Audigy 2 ZS card. No tantalum capacitors, but the ceramics used within the regulating circuit are pretty good. Conclusion? Seriously nice.