[Brammie]

I have a Sennheiser HD598 headphone connected to a Soundblaster XFi-surround 5.1 pro (my computer doesn't have space for an internal sound card).
Suppose I would connect some expensive DAC with a USB 2.0 instead of my current Soundblaster, would it make any difference for the soundoutput?
My current soundcard is a considerable improvement compared to the onboard soundcard wich my computer unfortunately has.
 
I'm a noob with regard to DAC's.

 

[PurpleAngel]

Quote:

I have a Sennheiser HD598 headphone connected to a Sound blaster XFi-surround 5.1 pro (my computer doesn't have space for an internal sound card).
Suppose I would connect some expensive DAC with a USB 2.0 instead of my current Sound blaster, would it make any difference for the sound output?
My current sound card is a considerable improvement compared to the on-board sound card which my computer unfortunately has.
 
I'm a noob with regard to DAC's.

DAC--Digital to Analog Converter.
The HD598 (50-Ohm) is very easy to drive, so I'm guessing the best external DAC you can get with in your budget is what you need.
What is your budget?
 
Fiio E10 ($70) USB-DAC-Headphone amplifier, with the WM8740 DAC chip, might improve the audio quality.
I would think you could find something really nice in the $150-$200 range.
 
Some ideas.
http://www.ebay.com/itm/NuForce-Icon-uDAC-2-Black-Headphone-Amp-and-USB-DAC-24bit-96kHz-/170783062634?pt=US_Amplifier_Parts_Components&hash=item27c376ba6a
http://www.ebay.com/itm/HRT-Headstreamer-USB-DAC-Headphone-Amp-/120852857673?pt=US_Audio_Cables_Adapters&hash=item1c23644349
http://www.ebay.com/itm/AUNE-HIFIDIY-NET-Mini-USB-DAC-Headphone-Amp-MK2-/350240347903?pt=US_Home_Audio_Amplifiers_Preamps&hash=item518bf396ff

 

[Brammie]

Thank you for your reaction. I wouldn't mind spending $150-200, that's a reasonable budget assuming that it lasts many years and that I profit maximally from this reasonably good headphone and possibly some other headphones I will use in the future.. I would however like some explanation why such a DAC gives better sound than my current soundcard. Especially since it might be quite difficult to try one out for me. What makes the difference? What differences will I hear?

 

[mikeaj]

There are two main parts:  the digital-to-analog converter and the amplifier that drives the headphones.  Depending on the circuit design, electronics used, layout, other small details of implementation, the performance of the system could be better or worse.  It's a matter of real-world systems not behaving perfectly linearly even though ideally you would want certain parts to do so, some compromises made in design, parasitic elements, etc.  
 
The DAC is probably okay.  The amplifier is generally not as good in a sound card like that, though it's not that bad.  Unlike some devices, it actually uses a chip that's intended for use as a headphone amplifier, the TI TDA1308 Class-AB stereo headphone driver.  However, it's got a slightly undersized electrolytic capacitor on the output, which can increase distortion a little bit and roll off the lowest bass slightly.  Also note that the system is limited to a certain output range—something like 1V rms—that would be insufficient to drive certain insensitive headphones to loud volumes.
 
Definitely there are differences, and definitely audible ones (at least with the right headphones: some won't be loud enough; for others, the distortion or frequency response issues could be nontrivial).  As for significant differences, maybe not.

 

[PurpleAngel]

Quote:

Thank you for your reaction. I wouldn't mind spending $150-200, that's a reasonable budget assuming that it lasts many years and that I profit maximally from this reasonably good headphone and possibly some other headphones I will use in the future.. I would however like some explanation why such a DAC gives better sound than my current sound card. Especially since it might be quite difficult to try one out for me. What makes the difference? What differences will I hear?

My best "guess", as I do not know for sure what DAC and amp. is in the SB 5.1 Pro
The Fiio E10 and SB 5.1 Pro both sell for around $70, so both should have roughly the same manufacturing (parts & labor) budget, the SB 5.1 Pro comes with a lot more (hardware) features then the E10, which leaves less money spent towards the DAC and amplifier section of the SB Pro 5.1, compared to the E10.