Advantage of External DACs
Nov 10, 2011 at 7:47 AM Thread Starter Post #1 of 32

jrmhng

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What is wrong with internal sound cards? I often see negative comments here about why on-board sound cards but never a detailed explanation as to why this is so and an external DAC may be superior. Can someone explain this to me or point me to resources that details this?
 
Nov 10, 2011 at 12:42 PM Post #2 of 32
I think the general theory is that (and the same applies to Hifi set ups), to avoid unwanted interference from other components in the audio signal line, its better to keep them away from each other. Computers have a lot of noisy parts inside and these can affect the signal and produce distortion. So if you are able to get the digital music data out of the computer and then convert it externally there should be no interference and therfore the sound should be purer.
 
The usb port on your computer can carry the digital data direct to an external DAC (soundcard) thus avoiding the often cheap Line out componants as these can also have detrimental effect on the signal.
 
Nov 10, 2011 at 12:50 PM Post #3 of 32
Every sound card I've had, no matter how expensive, has had some type of sound issue (hum, hiss, interference, etc...) and I also think this is the general reason that people give.
 
I also like having balanced outputs, and multiple input/output options so I don't necessarily have to turn the computer on to use the DAC, or I can send the output somewhere else without switching cords. You have a lot more physical panel space to work with if you have an external device, as there is only so much space on a single or double PCI faceplate.
 
Nov 11, 2011 at 8:46 AM Post #4 of 32
I wanted to sink $$ into something i could use on the desktop @ home , netbook/lappie transit/work so a sound card/DAC that would see it's entire life tied down to a motherboard's PCI/PCIe slot was a no no 
tongue_smile.gif

 
Nov 11, 2011 at 9:04 AM Post #5 of 32

The answer is simple, good external DACs give you both adaptive and asynchrous USB mode, the asynchrous one is INDEPENDENT from the master clock (MCLK) from the CPU, which is not really optimised for such applications since the actual audio transfer will have jitter and timing variations that are part of the master clock as well as jitter from the derived clock. The asynchrous USB mode, on the other hand, relies on an external master clock to handle USB transport, this reducing jitter by a 100 times. This might not be noticeable by the human ear, but definitely shows up in instruments, and onboard sound cards cannot give you 100% sound quality. End of rant.
Quote:
What is wrong with internal sound cards? I often see negative comments here about why on-board sound cards but never a detailed explanation as to why this is so and an external DAC may be superior. Can someone explain this to me or point me to resources that details this?



 
 
Nov 12, 2011 at 12:28 AM Post #6 of 32
Thanks for the answers.
 
So with a home PC, you guys have definitely noticed hissing and other interference?
 
With jitter, if it can't really be detected by the human ear, why does it make such a difference?
 
Nov 12, 2011 at 12:29 AM Post #7 of 32
I have absolutely no hiss or noise. A properly shielded sound card won't have any more noise than an external box, unless perhaps if the computer's power supply is crap (mine isn't).
 
Jitter doesn't make a difference, or at least a difference hasn't been demonstrated at any reasonable jitter level.
 
Nov 12, 2011 at 6:57 AM Post #8 of 32
Yep, that was what i said in the previous post, an external DAC wont make a huge difference that you can hear, 100 times less jitter from the asynchrous USB doesnt make an audible difference since jitter is already unnoticeable, the same thing as people making a fuss about THD (total harmonic distortion) when anything less than 1% is not audible at all.
 
Quote:
I have absolutely no hiss or noise. A properly shielded sound card won't have any more noise than an external box, unless perhaps if the computer's power supply is crap (mine isn't).
 
Jitter doesn't make a difference, or at least a difference hasn't been demonstrated at any reasonable jitter level.



 
 
Nov 12, 2011 at 7:04 AM Post #9 of 32
I used an external usb DAC and the difference is HUGE! If I have a listen through my MBP's port, it sounds like absolute rubbish now. Music become much fuller, smoother, non fatiguing, dynamic, etc. Then again, the difference is like living in Australia and living in Africa (no joke). YMMV
 
Nov 12, 2011 at 7:07 AM Post #11 of 32
Ah, that would most likely be the amp within your external DAC, not the DAC itself.
 
Quote:
I used an external usb DAC and the difference is HUGE! If I have a listen through my MBP's port, it sounds like absolute rubbish now. Music become much fuller, smoother, non fatiguing, dynamic, etc. Then again, the difference is like living in Australia and living in Africa (no joke). YMMV



 
 
Nov 12, 2011 at 7:21 AM Post #13 of 32
You do realise that if you plug your headphones directly into a DAC chip you get line-level signal right (usually about 2 volts)? It has to go through an amp in you external DAC. Most, if not all cheaper DACs like the nuforce, fiios have an amp integrated into it, so its not really a standalone DAC.
 
Quote:
Mine's just the DAC - no amp. Amps are another story.
 



 
 
Nov 12, 2011 at 8:35 AM Post #14 of 32


Quote:
You do realise that if you plug your headphones directly into a DAC chip you get line-level signal right (usually about 2 volts)? It has to go through an amp in you external DAC. Most, if not all cheaper DACs like the nuforce, fiios have an amp integrated into it, so its not really a standalone DAC.
 


 

 
Yeah, but it's not that significant. The chip is what matters the most.
 
 
 
Nov 12, 2011 at 8:38 AM Post #15 of 32
In any decent audio DAC, the output stage is generally much more important than the chip used. You don't need to head to the top of the line stuff to find DAC chips that measure stupidly well.
 

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