[DayofCalm]

So I realize similar questions have been asked before, but I kind of had trouble interpreting what I read and didn't really want to necropost or resurrect some old threads. As such, I figured I'd start a new one in an effort to clear up some of my confusion.
 
I'm a relatively new audiophile, so my gear isn't necessarily the best (by any means), but I have some respectable devices as this point. My headphones I regularly use as of now are Ultrasone HFI-580s, MTPGs, and Sennheiser IE8s (pretty clearly interested in bass). Sometimes I use my iPod touch to listen, but more often than not I use my computer.
 
My question relates to the S/P DIF port on my computer. I'm using an Alienware M17x, no more than a few weeks old. I'm not sure about how the sound card is in such a machine (is it worth investing in an amp/DAC?), but it evidently has this type of port. When I plug my headphones into one of the regular headphone jacks on my computer, the audio is pretty much how I'd expect it to sound. If I take out my headphones and plug them into the S/P DIF port, I can't tell if the audio is affected or if it simply gets a lot louder.
 
TL;DR: What does an S/P DIF port do differently than a normal headphone jack? If I have an S/P DIF port, should I bother investing in an amp/DAC (looking at the Fiio e7, or possible nuforce uDAC-2), or should I just go for an amp?
 
Thanks in advance guys. 

 

[Currawong]

The S/PDIF port is for digital output. If you're plugging anything in there and hearing sound, then it is sending out regular audio, not digital.   
 
The sound card in your computer is converting the music in digital form (1's and 0's) into an analogue waveform (the electrical form of regular sound).  An external DAC would take a digital signal from your computer (via the S/PDIF port) and convert it independently of your sound card. A sufficiently high quality DAC would do this better than the sound card, resulting in more clarity, if this is desirable.

 

[DayofCalm]

So an external DAC would convert independent of my sound card via my SP/DIF port. The amp/DAC I was looking at, the Fiio E7, seems to connect via USB. Not really sure how to interpret that, and whether or not it's good or bad
Would I have to buy anything additional if I sought to connect the E7 to my Ipod? e.g. Ipod>>FiioE7>>headphones. Seems like I would need a line-out cable; is there a distinction in quality of these? Simply curious about this whole amp/dac business to be honest, in terms of how it works and how worthwhile it would be to get one given what I presently have.
 
While I'm being a noob, I may as well ask: how do I check my sound card in my computer? In device manager, under "sound, video and game controllers", there are three things;  ATI High Definition Audio Device, IDT High Definition Audio CODEC, and Intel(R) Display Audio. Is the first one my sound card? If so, is that sound card any good or is it worth investing in the amp/DAC as planned?
 
Thanks

 

[th0m]

USB is just another way of transporting the digital signal, just like S/PDIF. Using USB though, there's actually no need for a sound card at all and the DAC will show up as a new audio device on your computer. Correct me if I'm wrong, but I believe "ATI High Definition Audio Device" is for the HDMI output from your graphics card. "IDT High Definition Audio CODEC" is probably the on-board sound card.
 
Any external DAC/amp would very likely be an improvement, but as always, you get what you pay for. I haven't heard the E7, but looking at its price, I doubt there's gonna be a night-and-day difference.

 

[JoetheArachnid]

Quote:

 
Any external DAC/amp would very likely be an improvement, but as always, you get what you pay for. I haven't heard the E7, but looking at it's price, I doubt there's gonna be a night-and-day difference.

 
The phrase 'famous last words' springs to mind. From what I've heard of the E7, it's still a sizeable improvement over most onboard sound cards, even on expensive compters.
 
As for LODs, I'd say that any will do. FiiO's own L1/L3 will do the biz very nicely (I own an L3) and are well built and cheap. Some people might tell you that a $400 LOD will sound much better - feel free to head in that direction if you're so inclined.
 
For your S/PDIF, it sounds to me like you've got a hybrid port of some kind on your laptop's sound card. It'll output sound or line out with an audio cable plugged in, but will output digital when connected to an external DAC. Talking about differences between S/PDIF and USB, think of it like this: USB is a two-way interface - information goes both ways and the computer recognises the USB device as a soundcard. With S/PDIF the digital signal goes only one way, and your computer won't see what's on the other end, it'll just send data that will then be decoded independently by the DAC. So you wouldn't be able to change any settings on a DAC conencted by S/PDIF from the computer but you could from a USB-connected DAC, amongst other things.
There's no real audio advantage to either, though USB is more convenient and S/PDIF is technically a purer digital signal.
 
That's probably not clear at all, but I hope it helps somewhat.

 

[th0m]

Quote:

 
The phrase 'famous last words' springs to mind. From what I've heard of the E7, it's still a sizeable improvement over most onboard sound cards, even on expensive compters.

You're probably right. Like I said I haven't heard it, only of it. It's just me being scared of any audio equipment costing less than a pair of jeans...

 

[DayofCalm]

 
Quote:

For your S/PDIF, it sounds to me like you've got a hybrid port of some kind on your laptop's sound card. It'll output sound or line out with an audio cable plugged in, but will output digital when connected to an external DAC.
 
That's probably not clear at all, but I hope it helps somewhat.

 
That makes a lot of sense. The only bit I would be curious about would be as to why, when I plug my headphones directly into the S/PDIF port, the volume is literally twice as loud as the standard headphone jack, even at the highest volume. It's like it has a capacity to drive my headphones better, which makes no sense, since I don't think there would be a built-in amp that outputs via my S/PDIF and not my headphone jack.
 
Also, this helped an incredible amount. Thanks so much, it really clears things up,and I appreciate the advice on the L3
 
 
Quote:

You're probably right. Like I said I haven't heard it, only of it. It's just me being scared of any audio equipment costing less than a pair of jeans...

This is probably true, but such is the life of a student budget. Especially when my parents don't actually know of $400 worth of headphones that I have, so I have to regularly hide them A sizable or expensive amp could be considerably more difficult...

 

[falis]

 
Quote:

There's no real audio advantage to either, though USB is more convenient and S/PDIF is technically a purer digital signal.
 
That's probably not clear at all, but I hope it helps somewhat.

Really depends on the rate and bit capability of the USB compared to that of the S/PDIF output.  The former tend to be less capable.  You'll need to find out whether that combined output wants coax or optical if you want to use it.
 

 

[Justinicus]

According to Dell, it is a combo digital/analog jack.
 
"(3x) Auto-sensing jacks for Line-out (2 line out; 1x SPDIF/Headphone)"
 
Not sure what's up with the two line-outs, but apparently you've been using one of them as a headphone jack, if Dell is to be believed.  Thus, your results are strange to me.  In the past, whenever I plugged headphones into a line-out (on a portable device -- never tried it on a PC), I got blasted. Presumably because it's bypassing the volume control and giving me full power.  I guess on a PC the OS is handling volume and other processing long before it gets to either the headphone or line-out jack. 
 
Peek into that jack, and see if there's a light inside.  If so, then it's one of the old combo 3.5mm/mini optical jacks like I used to have on my MiniDisc devices.  I've never seen a 3.5mm electrical S/PDIF connection, only RCA-type electrical, or fiber-optic.  Some people are big fans of electrically isolating their source from their audio system.  If you have a noisy machine, that makes sense.  Electrically noisy, that is.  Others are huge detractors of USB.  I've read a lot were people say that USB is a very noisy data bus.  I can see how it would be, since so many devices are electrically coupled, but it's been ages since I messed around with USB audio, and I don't recall my (very) old USB-to-S/PDIF converter conveying any noise at all to my MD recorder.  I've heard that there are other limitations to USB though -- something about a limit on the bitrate and frequency.  You might want to look into that if you're interested in high-res audio.