Quote:
Originally Posted by
shingo43 
Thank you
I think the asus essence stx is a good sound card, so I don't want to use a usb dac/amp to replace it. so that I have 4 options left
1. PC -> soundcard -> headphones
2. PC -> soundcard -> line-out -> amp -> headphones
3. PC -> soundcard -> SPDIF -> DAC/amp -> headphones
4. PC -> soundcard -> SPDIF -> DAC -> amp -> headphones
do you think option 2 will be better than 1? but the soundcard has a builtin amp, will it be duplicate to use 2 amps together?
for option 3 and 4, my concern is that will all digital signal be lossless? What I mean is computers are all about 0 and 1, so that no matter how expensive your sound card is, if it has a digital out, the In and Out will be the same? For example, my onboard soundcard has a digital out, so will the Out be the same if I play the same music on the on board card VS the more expensive Asus essense stx? and all the digital cables(no matter the price) will be lossless too? Am I correct?
If I was correct that only leave me option2?
Re: #1 vs #2
There are a couple factors to consider. First is whether the soundcard has enough power for the headphones. In your case it does. Next, is the output impedance. It should be lower than the impedance rating of your headphones. This is also true in your case. If either condition was not met, then an external amp would be a vast improvement.
Then there is the matter of background noise. Some soundcards are inherently noisy due to bad design, or can easily pick up noise from other parts of the computer like the video card, wifi, or power supply. I have read that the STX is well shielded and so on, so you may be good here too. Try it and see. But if not, then an external amp will also help. Like I posted earlier, you can max out the digital volume on the soundcard, and use the analog volume knob. The background noise is at a constant level, so when the music is made much louder, the noise becomes a much smaller percentage of the total signal. The amp's analog volume control will attenuate both the music and the noise equally. Personally I also like having an easily accessible device on my desk with a physical volume knob.
Re: Double amping
Many soundcards have a separate audio jack for headphones and for line out. The signals are amped differently for each one. Line out is good for linking to an external amp. Headohone out is the one with more power (but might lead to distortion if you amp it again).
Re: Digital 1s and 0s
Yes, one of the benefits of digital is that it can be transmitted and retransmitted countless times with no loss or degradation. However, that usually requires good transmission protocols, such as the TCP/IP that we use for internet. In audio, the standard is S/PDIF. This is a one way protocol with no error correction. If the sender screws something up, the receiver can't request for it to be sent again. Why this is still being used is beyond me.
You'll probably see "jitter" being discussed on Head-Fi. This happens when the sender and receiver are not totally in sync. It's the most commonly cited cause for differences in digital transmission. However to put things in perspective, studies have shown that distortion from common jitter is almost inaudible. Your mileage may vary. This is another hot topic in the audio holy wars.
So is the onboard digital out the same as the STX digital out? In theory yes. But maybe the STX has more stable drivers and uses less CPU. Maybe the onboard SPDIF output carries analog noise along with the digital signal. This noise may affect the performance of the external DAC. With the STX I believe you can also apply effects to the audio sent out over SPDIF, like virtual surround sound. Should be useful for gaming or movies.
