Sound Card- vs -DAC, what do I need
Nov 14, 2008 at 9:58 PM Thread Starter Post #1 of 16

FL210

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My current equipment:
1, Laptop with tons of FLAC/APE music
2, Headphone Amp--Little Dot Mk III
3, Headphones--AKG K701

My question is:
Do I need a sound card or DAC to get the best of laptop FLAC/APE music through my headphones?
What input/output port shourd the SoundCard/DAC have?
 
Nov 15, 2008 at 1:52 AM Post #5 of 16

Seamless Sounds

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A dedicated DAC is only responsible for converting digital signal to high quality analog signal. DAC can be balanced as well in which PC's can't (they don't have an XLR output). However it's garbage in, garbage out. If your onboard soundcard produces bad digital signal, your DAC will suffer as a result along with your headamp and headphones. A DAC is not responsible for cleaning up digital signal, it only converts it.

That said, what you need is a really good DSP sound card to process or create the digital signal itself. I'd recommend using digital spdif like coaxial or optical since usb doesn't block out EMI. Also, a soundcard can help take the workload off the cpu. So to get the best out of everything, you need a dedicated DAC and a dedicated DSP. Otherwise DAC comes first imo.

Hope it helps.
 
Nov 15, 2008 at 2:10 AM Post #6 of 16

FallenAngel

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Quote:

Originally Posted by HeadFi Fanatic /img/forum/go_quote.gif
A dedicated DAC is only responsible for converting digital signal to high quality analog signal. DAC can be balanced as well in which PC's can't (they don't have an XLR output). However it's garbage in, garbage out. If your onboard soundcard produces bad digital signal, your DAC will suffer as a result along with your headamp and headphones. A DAC is not responsible for cleaning up digital signal, it only converts it.

That said, what you need is a really good DSP sound card to process or create the digital signal itself. I'd recommend using digital spdif like coaxial or optical since usb doesn't block out EMI. Also, a soundcard can help take the workload off the cpu. So to get the best out of everything, you need a dedicated DAC and a dedicated DSP. Otherwise DAC comes first imo.

Hope it helps.



Of course sound cards can have balanced outputs, usually they are 1/4" TRS.

You are correct about garbage-in = garbage-out; most onboard are not bit-perfect and usually aren't timed properly (jitter).

DSP as in Digital Signal Processing - assuming we're mostly interested in playback, we simply want an interface to the PC, soundcard (PCI) is just fine. Output using S/PDIF is OK, but depends on implementation, optical in general isn't that great because the to/from optical introduces timing errors. Coax is better, but should be done with a pulse transformer. Quite common with higher end cards.

About sound cards taking load off CPU, it REALLY REALLY doesn't matter unless you're running on a 10-year-old PC. Seriously, really not something to ever consider with any PC bought in the last 5 years.

USB vs S/PDIF : EMI is the least of your concerns, read a few of the other threads, there are many.

Quote:

Originally Posted by FL210 /img/forum/go_quote.gif
Thank you folks. Any idea what the difference between SoundCard and DAC?


See above for most of the answer. Generally Soundcard is a transport (receiver for PC) and DAC. Standalone DACs are just DACs, no transport, they need a transport to feed them content (using S/PDIF, USB, I2S, whatever).
 
Nov 15, 2008 at 3:31 AM Post #9 of 16

Purist

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I'm relatively new to the PC-as-source thing and was a bit confused over the Card vs DAC debate. I was pushed into getting a USB DAC (FubarII) as the drivers for the on-board card kept giving me BSOD (took ages to figure that one out).

There is no comparison between the SQ from the Realtec ALC850 and the FubarII. If you play games and need the 7.1 DSP and all the rest then you're probably best off with a sound card but if you're just into music then I highly recommend the DAC route.

The USB route I've gone down is the easiest, no drivers, no co-ax etc. but there may be some SQ issues (search the forum). I'm very happy with my system for the moment (FubarII, Meier Corda PreheadII SE, HD-650), it's not exactly High-End but I enjoy the sound (listening to a mix of madrigals and metal now).

USB DACs are cheap, you should be able to buy a used one here and if you don't like it in a month or so then sell it again. You'll know whether it floats your boat or not and it'll have only cost the postage. I feel it's worth the effort.
 
Nov 15, 2008 at 3:39 AM Post #10 of 16

Sherwood

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Quote:

Originally Posted by Purist /img/forum/go_quote.gif
it's not exactly High-End but I enjoy the sound


Don't put your system down. Those are all excellent, well built components. They might make the high-end forum around here, but they certainly provide you with phenomenal sound. I'm guessing the entirety of the rational world would see that setup as pretty darned high end.
 
Nov 15, 2008 at 8:48 PM Post #11 of 16

jt4266

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Quote:

Originally Posted by HeadFi Fanatic /img/forum/go_quote.gif
If your onboard soundcard produces bad digital signal, your DAC will suffer as a result along with your headamp and headphones. A DAC is not responsible for cleaning up digital signal, it only converts it.


So if the on-board sound cuts in and out(not going to replace the motherboard for a 3 yr old laptop) I would need an external soundcard and a DAC to have reliable music going to Audioengine A2's?
 
Nov 15, 2008 at 9:04 PM Post #12 of 16

rembrant

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No get a DAC that is also a PC sound card. You plug it in through USB and your done.

If you want 7.1/5.1 surround sound for any reason, there are several USB sound cards that will provide that. That would be the only reason I could think of that you would need a USB sound card.
 
Nov 17, 2008 at 7:30 PM Post #13 of 16

jt4266

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Quote:

Originally Posted by rembrant /img/forum/go_quote.gif
No get a DAC that is also a PC sound card. You plug it in through USB and your done.


I apologize for my lack of knowledge but I'm here to learn - How do I know if a DAC acts also as a soundcard. My price range would be below $150.
 
Nov 17, 2008 at 11:26 PM Post #14 of 16

rembrant

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No apologies needed. This crap gets confusing sometimes.

Any USB DAC based on the PCM2702 like the Alien DAC and many others are driver-less USB Sound cards for windows and supposedly MacOS as well. I don't know about the latter.
 
Nov 17, 2008 at 11:53 PM Post #15 of 16

FallenAngel

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I'm really REALLY going to have to add this to my signature because I feel like I'm writing the same response to the same question every week. This is the breakdown of a digital system.

DAC : Digital to Analog Converter. That's IT. It does nothing else.
DACs have digital receivers. These receivers accept one of the following digital input : USB, S/PDIF (optical or coaxial), AES (a form of S/PDIF) or I2S.

TRANSPORT : A device that takes digital media (reads from CD, hard-drive, USB key, whatever) and outputs a digital signal in one of the formats above.

Amplifier : Takes an analog signal (I repeat, ANALOG, as in not digital) and amplifies it. Again, THAT'S IT, nothing more.

For a digital system to work, all 3 must be present. Transport -> DAC -> Amplifier.

-----

Most get confused by the idea of a "USB DAC" because it includes the first two (Transport and DAC). A "USB DAC" is in fact a Transport and DAC, it connects to your computer (the media) and you are able to send a digital signal through it to a DAC; the DAC just happens to be in the same box (and in the case of PCM270x/PCM290x; on the same chip).

A soundcard is another example of a transport - it connects to your computer (the media), and outputs a digital signal. Again, most sound cards have a DAC built into them, and also an amplifier following the DAC. Just because these are all on one board does not mean they are not separate components in the chain. It's simpler to see it separated that way for clarity.

-----

rembrant : USB 1.1 Audio drivers are supplied with most operating systems so devices that comply with the standard (such as PCM2702E in the AlienDAC) will work as "plug-and-play" with Windows, MacOS and most distributions of Linux.
 

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