Thanks all for the replies stv, cel and purple, The SBZ has all the DSP / Gaming features that I want; using it would appear to utilise the full functionality of the Sound Blaster control panel suite when using optical/SPDIF out (this is true isn't it?). 50 pounds ($80) is a lot perhaps to pay for just the DSP / Surround processing but that's just what I need.
Adding a DAC and Amp via SPDIF out to the Audio_GD 11 or 15 is frankly expensive (This looks good too http://www.mav-audio.com/base/product/tube_magic_d1); and way beyond what most would pay using a computer. I'm however wiling to cough up the cash for the best gear without going bananas. TBH, from my research the Essence STX and even the Creative ZxR look fantastic value for money.
Anybody here at the tail end of this thread.... I was being very specific about my needs. I chose the headphone 1st (you really oughtn't to do this perhaps - I'd heard the Philips Fidelio X1's and based my decision around them.... maybe I'm completely wrong in doing this?); then I chose the surround sound technology for gaming (SBZ). Wanted superb music playback too. Then I posted this thread.
stv.. thanks for the info on 'double amping', I never understood how a soundcard's headphone amplifier could (sort of) successfully be a preamp to an external amp (just to reduce the resistance.. am I being too uptight about this?). cel and Purple too - many thanks guys.
Edited by SaLX - 10/5/13 at 9:24pm