As according to a techgage review
of the STX, it says that:
"At the heart of the Xonar Essence STX is the ASUS AV100 audio processor, which is based on the C-Media CMI8788 OxygenHD processor ... The AV100 can process up to 8 channels of audio, and it's used in ASUS' Xonar D1 and DX, but in this application with only two channels in use, it produces even more pristine audio clarity. The AV200 audio processor used on the Xonar D2, D2X, and HDAV1.3 cards, which is a higher-binned version of the CMI8788 processor, is able to maintain the same audio quality with all eight channels passing a signal at the same time, but the AV100 is able to achieve the necessary levels of performance in a two-channel application."
Why would they not use the AV200 in the 7.1 edition of the STX, (being the ST)? I just figure that the AV200 would be more advanced than the AV100? But specs don't always tell the story I guess...
Surely they'll just call this 'new' card the Essence ST Deluxe (as it has the H6 DAC expansion card)?
I run Ultrasone HFI-580 cans or my Logitech Z5500Ds, so I too have been waiting for a multichannel version of the STX.
In any case, I'm really interested to see how the Essence ST goes against the Auzen Forte!