[Asterra]

 
Hi folks.  I got this card yesterday and got it up and running with my similarly new headphones.
 
My Xonar Essence ST is taking over the audio output (to headphone) functions of what I was originally using, which was my
motherboard's onboard audio.  Gigabyte EX58-UD5 mobo with Realtek ALC889A audio.  It did its job well, but allowed for considerable audio leakage and also was barely able to power my previous headphones which had 150 ohms impedance.
 
Now, riddle me this: As far as I can tell, the Xonar Essence ST is deficient in audio-in options.  It has an "aux input" whose description seems to limit it to unique internal audio concerns.  This basically means I need to stick with the onboard audio to get any input.  The onboard audio includes SPDIF and analog.  Both work.  I can hear both through the audio out from the onboard audio.  However, when switching the "default" playback to the Asus headphones, the only audio in I can hear coming from the Asus is the analog input from the onboard audio.  The SPDIF input does not get added to the Asus mix.  In fact it remains tied to the onboard audio's output, despite the fact that I have told Windows (7) that it is no longer the default playback device.
 
I know this issue may not necessarily be a problem with the Xonar Essence ST or its drivers (which I grabbed fresh from Asus' website), but it would still be nice if I could actually take advantage of fewer DAC/ADC conversions, the way I intended. ;p  If anyone has any insight as to why this is happening, or how I might go about fixing it, I'm all ears.  Thanks.
 
(While I'm at it, can anyone name the go-to "opamp" replacements for this card?  I feel like my new HD650s don't sound a great deal better than my old HD265s and am certainly looking for options.)
 

 

[Asterra]

Hmm.  I may have just solved my own issue.  Hah.
 
Still interested in the opamp question, though.  Maybe there is a thread about it.