I've just completed a new build built around a GA-P55M-UD2. However the output volume from my Asus Xonar DX is incredibly quiet, almost inaudible. Boosting it to an audible level results in distortion.
I've done a range of tests to establish it's a motherboard/PCIe issue. It's not a problem with the card as it works properly with my old motherboard (GA-P35C-DS3), it's not an OS or driver problem as it's replicated in Windows 7 and in Linux, and it's not a problem with my headphones/speakers as the volume is fine when the card is in my old rig or when they're being driven by the onboard Realtek sound.
The card is compatible with 1x, 2x and 4x PCIe slots, and is in in the 4x PCIe slot running off the P55 chipset. I've tried both F3 and F4n bios versions. All PCIe settings in the bios are at their default.
Anyone got any ideas?
Edit: Also it's not a PSU/power issue (the card needs a 4-pin power connection) as the problem is the same when the card is being powered by my old PSU. If there was a power issue it's likely the driver software would report it anyway.