[JoeinLA]

First post - I've been doing ALOT of research  and reading and, this forum has proven invaluable!  I was hoping to ask some final questions regarding PC gaming and sound...  
 
Just as background, I'm using the Asus Maximus V Gene motherboard, which has the "SupremeFX III" sound setup (apparently, the Realtek 892 chipset).
 
As I understand it, if I want "surround sound" through headphones, then I need to have either (a) a soundcard that supports Dolby Digital Live OR some other DSP that will "convert" the games' surround sound output into some sort of emulated stereo surround.   
 
1.  If I have a AV Receiver (specifically, a Denon AVR 4311Ci), then I *THINK* I can just output (either HDMI or analog) to the AVR and use the AVR's simulated surround sound to get "surround sound" through my headphones while gaming?  I.e., I don't need to buy a dedicated sound card, since the AVR is doing everything to the signal?  I believe I'm correct is saying that if use the Toslink optical out, then my receiver will only receive a stereo signal, whereas either the HDMI or the analog connection will provide the "full" sound information from the game?  Would the "quality" of the Denon's simulated surround be good/bad compared to the Dolby Live processing?
 
I had decided on buying a Xonar Essence STX, but then realized that I had this very expensive AVR sitting around that had multiple zones, so I'm hoping I can use the Denon 4311 and not have to spend more money on a sound card.  It seems like if you have an AV receiver, then a sound card isn't needed (or useful)...?
 
2.  If I don't have a dedicated headphone amp (or other "audiophile" type equipment) would buying something "extreme" like the Senn HD800 or Beyer T1 be completely overkill...?  What would be the "upper end" of reasonableness if I'm just going to be listening to these through the Denon 4311?  I prefer classical, hard rock, metal, and U2  I've read MLE's thread (multiple times) and am thinking of going with either the Senn 598-650 line or the Beyer 880 (or the new Custom One but haven't read any reviews yet).
 
Thanks in advance!

 

[JoeinLA]

FYI, I just ordered a DT990 Premiums 250 Ohm for $270 off of Amazon.  Thought it was a good price and I considering these (or the 600 Ohm, but was concerned about powering the 600 Ohm ones) or the 600/650's; but the price of the 990's seemed pretty good so I jumped on 'em.
 
I may just break down and get the Asus STX or Phoebus (aware of the current driver issues) just b/c it seems "simpler"...

 

[PurpleAngel]

Your Asus motherboard already comes with a S/PDIF Toslink optical output.
So just run optical from the motherboard to the Denon.
Optical can carry up to 6.1 audio (compressed), but in this case the best you would send thru optical is 5.1.
If your graphics card has HDMI output and your monitor has HMDI input, you could run HDMI cable(s) from the computer to the Denon and the HMDI from the Denon to the monitor, which would give you 7.1 audio (8-channel PCM audio).