Well Creative calls it a DAC, but yeah their external sound card, like the SoundBlasterX G5 and E5 that Forty6 mentioned.
And yeah, considering I prefer headphones speaker outputs are more or less completely useless to me.
The G5 and E5 seem nearly identical, both externals and the ZxR use the same audio processor, with the built-in beam-forming microphones with Crystal Voice(which the ZxR also features) being the main reason the E5 is ~$4-50 more, along with that the E5 uses SBX Pro Studio while the G5 uses the (newer?) BlasterX Acoustic Engine. Seems like both do 7.1 Virtual Surround though, whereas the ZxR can only do 5.1(is that really much of a con?)? Some reviews have complained that the ACM module included with the Zx/ZxR impacts sound quality rather negatively as well compared to connecting directly to the outs on the card(anyone else noticed this?)
I'm also somewhat concerned about the quality of the headphone amps in them. Some tech site reviews had reported that, despite their 600ohm ratings they had trouble driving high impedance headphones properly on the internal sound cards? Which considering I intend on getting a 150ohm set as soon as they're on a decent sale is somewhat disconcerting. Anyone else experienced this or maybe the reviewers just got a bad card? Do the external cards amps perform like they should? And has anyone compared sound quality between the external cards and the Z-series internal sound cards?
Price comparisons included just for the heck of it
E5: $170
G5: $129
ZxR: $210
Zx: $90
Z: $70
DAC or external sound card, guess each company decides on how they want to discribe their product.
The is really no compelling reason for buying a 600-Ohm headphones, just because they are 600-Ohm.
Some of my best sounding headphones are 32-Ohm and 40-Ohm.
If your going to buy a 600-Ohm headphones, then you really should be investing in something like a nice tube headphone amplifier, to drive them.
My guess is the way the Creative ACM manages volume control might effect the audio quality with certion headphones but i'm not the expert on that.