[BlackSushi222]

Hi people at head-fi, I need some advice for my friend's PC which has an onboard soundcard which is the Realtek ALC888.
 
This would help me too, as it would clear things up, since me and him are total noobs at how audio works.
 
His motherboard which has the ALC888 has, what I believe, is the standard "analog" output? 6 of them for 5.1 surround I guess.
And I noticed on my sound card (X-Fi Titanium) has 2 extra "digital" outputs.
 
With his headphones (HD555) connected directly to the analog, his songs sound pretty good. Actually just as good as on my computer. But we did notice some hissing.
 
When I connect my headphones (RP-21) directly to analog, it sounds acceptable to me as well, but I do also notice the hissing.
 
Now I read some stuff on people using uDAC + Amp, or just uDAC (which I'm still confused about) in order to elimate the hissing and get a cleaner signal and sound quality I think?
 
But in my friend's case, since he doesn't have a digital output like me, is there no chance for an add-on (unless he buys a new sound card)? Or am I understanding it wrong?
 
Thx.
 

 

[revolink24]

Hi there.
 
Sound reproduction out of a computer happens in two stages - the digital to analog conversion and the line-level amplification. What happens with any sound card, both integrated and that X-fi (Incidentally, I have experience with both) is that there are two circuits, one to convert the digital audio (in the form of ones and zeros, fed through as "samples") to analog audio at what is known as line-level. This is a very low volume audio signal designed to be amplified later on. Depending on the quality of the digital to analog conversion, the audio reproduced may have a plethora of problems. In your case, it is causing what is known as a low signal to noise ratio, in which the amplification circuit is not only reproducing the music, but also the noise produced at the line-level. (Most likely, anyway.)
 
Now that uDAC has two functions. Like the onboard audio and the X-fi, it is split into two circuits, the first's job being converting all the ones and zeros into analog audio, which then needs to be amplified. This results in a line-level audio signal being outputted through the RCA jacks on the side of the uDAC. However, the uDAC also has a built in headphone amplifier that will amplify and adjust the volume of the line-level signal, allowing you to use headphones with just the uDAC and no additional amplifier. The RCA jacks simply bypass this amplification to use with an external, higher-quality amplifier for speakers or headphones or whatever you want.
 
 
Now for the 6 outputs on the ALC888. While it likely does have 6 ports on the back, the chances of them being the 6 channels of 5.1 audio is slim to none. Most likely, there are three or so ports designed to be headphone-out, line-in, and microphone-in ports. While the ports functions can often be swapped using realtek software, it is best that they not be. Then you should look in the computer documentation for the information on the other ports. Each port can probably output up to three channels of audio using what is called a TRRS connector (Tip, ring, ring, sleeve) which looks like a headphone plug with an extra ring. For example, a single port could be responsible for the front left, front center, and front right speakers in an audio setup.
 
Using an external DAC and headphone amplifier, as two or one units, would definitely improve the sound quality. Computer built-in audio circuits and mainstream cards like the X-fi are built to a price, and are quite susceptible to interference from the massive amount of electronic interference inside the case of the computer. That uDAC is powered by USB and acts just like any other sound card, just like the X-fi would in a computer. In short, a DAC/Amp combo is just like a computer sound card but tailored for a higher-end market.
 
I hope that was at least somewhat helpful. If theres anything I didn't answer that you would like to know, feel free to ask.

 

[BlackSushi222]

Oh wow, thx for your informative reply!
 
Ok so a DAC/AMP acts like a soundcard, but different hardware?
 
So if you were to use DAC/AMP, you'd have to disable/remove the soundcard right?
 
What exactly can the digital output out of my soundcard do?
What do I need to have my headphones be able to connect to it? DAC, not a uDAC right? Or is it not used for that purpose?
And does that cause an improvement in sound as well?
 
And lastly, my friend has no other choice but to upgrade right? He can't get any more out of his soundcard right?
 
Lol, sry for asking so much.

 

[revolink24]

Firstly, a DAC/Amp can absolutely act like a sound card. External USB DACs with built in amplifiers are simply two-channel external sound cards, albeit minus the fancy processing that many sound cards can do. You would not necessarily have to remove the sound card in your computer - they can act independently of each other, just set the output of your music player to the DAC and you would be set.
 
Now its a bit of a different story if you use the digital output of your sound card. If you were to do that, you would be using your sound card as what is known in the audio world as a transport, or simply a means of transferring all the ones and zeros (samples of digital audio) to the external DAC. Since the uDAC is USB only, you would not be able to use the sound card as a transport. Oh, and if you do use a sound card (including onboard audio) as a transport, that remains your sound card as configured in windows. Using either the digital out of your sound card or a USB DAC would have about equivalent performance gains in terms of audio quality. There really isn't that much more to be had out of a sound card like that - internal sound cards are good upgrades, to a point, but in the end they just don't stand up to dedicated DAC units.
 
This thread is a great resource if you're looking to find DACs - notice that that list also includes various sound cards.
 
If you want to use it as a sound card, you should be looking at something with USB input. If you want to use the onboard sound as a transport, look for digital inputs which can be different depending on the outputs of the sound card on the computer. If it is an optical (Toslink) output, you should look for an optical input. If it is a Coaxial (looks like a standard RCA audio plug usually) then look for a DAC with coaxial input. That said, USB DACs usually present better value for money.
 
The uDAC is a product by nuforce, and is excellent if you can afford it. It has a good DAC circuit and a decent headphone amp circuit, and is powered by the USB bus, therefore not requiring an additional power adapter.
 
http://www.nuforce.com/hp/products/iconudac/index.php
 
If you are interested in a dedicated amplifier as well though, I do recommend something like the USB Fubar II from Firestone Audio: http://www.audiophileproducts.com/fubar2
That would convert it to an analog signal at line-level and require an additional amplifier. But if you're just looking for something to get started, the uDAC is great because that can act as an amplifier itself and as a DAC later if you (or he) want(s) a dedicated headphone amplifier later on.

 

[BlackSushi222]

Amazing info revolink24! Thx so much.
 
I finally understand this whole setup thing now xD.
Your input was GREATLY appreciated!
I think I'll start off with a uDAC then, and I'll see how it goes from there .

 

[revolink24]

You're very welcome, and good luck.