[Sploosh67]

So I was told that essentially what a usb DAC amp is going to do is bypass the soundcard. In my mind that essentially means the soundcard is, well, useless. So, if that's the case, is it still necessary to own one? If it is, would the quality/price/any factor matter to the sound produced through the amp, or the action of a computer? If the soundcard is not useless or is not bypassed, then what is actually happening?

 

[Head Injury]

A sound card is a DAC. Everything that can process and play digital audio includes a DAC. Your motherboard includes a DAC. The DAC is what converts the bits of digital audio into analog electrical signals, that can then be fed to an external amp or amped internally to drive headphones/speakers. 
 
An external USB DAC is going to get a raw digital signal from the computer. It does its own conversion. So the internal sound card does no conversion, and is effectively bypassed.
 
You don't need an aftermarket sound card (like a Creative sound card) if you plan to buy an external USB DAC. On the other hand, if you have a good aftermarket sound card there might not be much reason to buy an external USB DAC, because the sound card itself is a good DAC.
 
Internal sound cards are still useful if you need surround sound processing for gaming. You'll need to plug headphones into the sound card though, though some can pass the processing along as a digital signal via coaxial or optical to an external DAC. Won't work with USB DACs without a messy converter.

 

[Sploosh67]

SWEET! Thanks for the info totally answers my question and more if I was going to, say, build my own computer, therefore having to buy a sound card, could I just not and use a USB DAC? Or would I need per say a cheap one to get things working on the computer?

 

[Elysian]

Diminishing returns kick in very early with DACs.  Get a $300-350 DAC like a gamma2 and it will treat you very well for a long time.  The nice thing about external DACs is that they are easily moveable, so you can use it interchangeably between computers.
 
For casual users, getting S/PDIF or USB out of the motherboard is fine.  Mobos like the Gigabyte X58A have perfectly fine implementations of S/PDIF, unless you want to go all-out and get a PCI USB card like the SotM, which is only a good option for a hardcore audiophile.
 
I haven't tested it yet, but the Musical Fidelity V-DAC II looks interesting as a budget async USB DAC solution.  I personally do not like the USB implementation on the gamma2 and used S/PDIF for it.
http://www.amazon.com/Musical-Fidelity-V-DAC-II-MKII/dp/B005K8CSZ2
http://www.musicalfidelity.com/products/V-Series/V-DAC/V-DAC.asp
 
I like the V-DAC II on paper because it's async USB and supports up to 24/192.
 
TL;DR, skip the PCI sound card, get a mobo with S/PDIF out (unless you know you're only going to use DACs which support async USB or you're going to buy an asynb USB converter like the Audiophillleo 2), and get a $300-400 DAC.  Head Injury gave you good advice.

 

[Sploosh67]

Well I plan on getting an Aune Mini USB DAC. My question is mainly on what is going on in the computer and does the computer /need/ a sound card to function or can I just hook up the DAC and listen to that with the computer completely lacking a sound card. I plan on building one soon as well so I want to know how to address the issue.

 

[Head Injury]

If you want an external DAC and you don't want surround sound processing for your headphones, don't bother with a sound card. If you do want surround sound processing for your headphones (for games, maybe movies), get an internal sound card and don't bother with an external DAC.
 
What headphones are you using?

 

[Sploosh67]

When I build a computer....will I need to buy a crap sound card for it function properly or can it run just fine with one completely absent from the system????? AKG K271 MKII's and Grado SR80i's

 

[Head Injury]

I swear I've answered that twice already. No. A sound card is only a DAC/amp. You're already buying a DAC/amp.

 

[Sploosh67]

Alright, sorry. Just for some reason it feels like a computer would need one connected to it internally. At least in my mind. I guess I just wanted a direct answer...

 

[Elysian]

Think about it in terms of digital and analog.  The signal that comes out of a 'headphone out' port on an internal sound card or mobo sound is analog.  There's a chip on your sound card/mobo that handles the D/A (digital-to-analog) conversion.
 
You need to get that D/A done somewhere, otherwise you won't hear anything.
 
The option brought up earlier is that you can just have your mobo output a digital signal, then take care of the D/A conversation on something like a gamma2.  Consequently, the gamma2 has analog out ports (such as a 'headphone out').
 
The only reasons to get an internal sound card is if:
1) You need surround sound
2) You're strapped for cash
 
It's a bit more complicated re considerations for high-end gear (once you're dropping $500-1000+ per component), but I'm assuming you're not in that category.

 

[Sploosh67]

Far from XD thanks for the description though

 

[Head Injury]

Quote:

The only reasons to get an internal sound card is if:
2) You're strapped for cash

This is a little too simple. Some sound cards outperform external DACs twice their price (or more). It's about value, not price.

 

[Elysian]

I've never been impressed by anything around the Auzentech Prelude and Creative Titanium quality range, modded with blackgate caps and new opamps.  Maybe things have gotten a lot better in consumer sound card-fi in the last two years, but I haven't heard it.
 
The nice thing about consumer-fi is that there's far more parity in the sub-$200 range than there was 5-10 years ago, but most sub-$500 DIY gear (and gear from smaller but reputable shops) I've heard kills the stuff regularly praised on these forums.

 

[NamelessPFG]

What about having a sound card with gaming features feed an external DAC through S/PDIF?
 
I've thought about doing this with my X-Fi cards down the road, simply because I don't want to give up EAX 3-5 support (yes, I play a lot of older games still) and especially CMSS-3D Headphone...but there's still the very likely possibility that they're holding back my Stax Lambda in some fashion.

 

[Elysian]

If you're just going to do a digital signal out (Toslink, coax, etc.), there will be no difference between the mobo and consumer sound cards.  The only point to getting a consumer sound card is if you want surround sound, or want a reasonably competent analog out (not digital out).  I hear absolutely no noise on the Realtek 899 implementation on my Gigabyte X58A-UD3R, have tried a few Xonar cards, and have concluded that I hear no difference at all going from the optical S/PDIF (toslink) out from the sound card to the mobo toslink, just like everyone says there's no difference.  I did hear an improvement going to 75 ohm coax, and the X58A-UD3R supports both Toslink and coax, so I removed the sound card from my desktop since it's now completely unneeded.
 
There are specialized pro cards (supposedly less jitter (doubtful) among other benefits such as AES/EBU output), but those begin at MSRP $650+.  I would not even consider touching those if your source isn't in $5k+ territory.
 
I'll agree there is a big difference between notebook and desktop sound implementations, but the difference I hear between a good Realtek component and a $100-200 sound card is marginal at best.