Originally Posted by fss69
Isn't the headphone output on the backslot for the STX? I have the Essence ST - PCI version, but I don't recall if there was a front panel connection. (Sorry, I never use the FP and I can't check, I'm on my laptop.) If you're still connected to onboard - there's your problem right there. Also there might be some EMI problems if your sound card is too close to another PCI/e card. Space them out if you can.
There is a headphone jack at the back, but there's also a connection internally on the card for the front panel. I believe the front panel jack is the one that is amplified. It's definitely not connected to the on board sound as I can toggle the sound on the Xonar app between the speakers/rear headphone/front panel with the app and it routes it to the right place. The sound card is right next to the video card. Unfortunately it's the only mounting option on my board so moving the sound card is not a possibility.
Originally Posted by obobski
very likely the FP cable, especially if you've routed it under or around something like the mainboard or power supply (the shielding on some internal wiring jobs is a joke)
as far as the EMI gremlins, wouldn't pay them much mind, if you've got no interference from the rear outputs, card itself is fine, issue is somewhere between it and your transducers
That's what I'm suspecting. I'll have to check where it's routed through. I don't think it's under the MB, but it's been a while since I've cracked the case open to see where the FP I/O cables go. I know it's not near the power supply since that's at the back of the case but in any case I'll make sure it's not running near any power. I kind of wanted to use the front panel since that's where I'll be plugging in my headphones. The cable is a bit too short to use the one at the back.
I haven't seen any "higher quality" front panel I/O replacements so I guess replacing the cable is out of the question as well...
Thanks for the suggestions guys!