The MX25 up close
In the box
Diamond sells the MX25 in an inconspicuous white box, which isn't much of a problem for a mail-order item (no need for big, flashy store displays). Included is the MX25 breakout board itself, stored in a standard anti-static package, the 34-pin cable used to connect the board to the MX300, an installation CD to update the MX300 drivers to support S/PDIF out, and an instruction manual on how to install the card and included software. The installation CD also comes with an updated version of Zoran SoftDVD, with included support for 5.1 output through the MX25's S/PDIF connector.
The board itself
Let's take a closer look at the MX25 itself. What looks like a fairly complex circuit board consists of only a few small components. 90% of the board is empty space. In fact, from the cut-out of the cable and the lead on the board traces, the only real connection going to and from the board is the S/PDIF pulse and a ground cable. The I/O backplate houses a lone S/PDIF out connection.
What? That's all I get? Well, in a word, yes. The MX25 provides one coaxial S/PDIF Output, which with the included software can redirect MX300 signals to the MX25. While the board layout has outlines for several backplate connectors, as well as internal S/PDIF and I2S connectors, they remain uninhabited, an unused template for the never-to-be-seen MX-50 product. For reference, Aureal's reference "SuperQuad Digital" Vortex 2 board is able to pack on an optical toslink SPDIF out in addition to 2 stereo out, line in, mic in, and joystick/midi.
There is some good news, though. Diamond certainly didn't skimp on the design of the MX25 - you'll find the same attractive black plate as on the MX300, and the single coax connector is gold plated, as are the connectors on the MX300.
The MX25, front and rear
The MX25 was a breeze to install. Since it's a breakout board design, there is no need for a free PCI or ISA slot (and thus no extra IRQ is required), but you DO need a free slot, at least 1 slot away from the MX300. The cable that comes with the MX25 is more than an inch shorter than the SBLive's, so if you are trying to fit a card between the MX300 and the MX25, make sure it's not more than an inch longer than the MX300 itself.
The software was easy to install as well, overwriting your current MX300 install with version 4.06.2017. This isn't the latest available version available from Aureal (2035 beta is available at www.aureal.com), but the reference drivers with support for the SuperQuad;s digital optical out seem to work without problem on the MX25, also allowing for selectable sample rate of 32KHz, 44.1KHz, or 48KHz.