Originally Posted by pkgk1
I just need a soundcard, and possibly an amp (should I consider a DAC? Should most soundcards have decent DACs?)
However, I also want to pick up some 5.1 surround for movies and "sharing" audio when friends are over (looking at logitech z5500)
I'll need some way to hook up 5.1 to a surround sound, and a pair of cans to my computer, hopefully with only minor bottlenecks in sound
I was thinking of this possible setup:
Simply get a xonar ST, and use the front panel audio connector, and plug in my 990's to the front panel. (Or should I use the 6.3mm connector and plug it into the back of the soundcard)
I read online there's a way to hook up 5.1 surround through the coaxial port (SPDIF)
^^^^^^^ What do I need to buy to hook up 5.1 surround with the ST through the coaxial port, also, is the xonar ST's amp good enough to power the 600ohm 990's??
I own the DT990s and the Xonar STX (modified). You didn't mention what computer and OS you're using, so I will assume Windows XP or 7 and good power supply in your computer.
IMO, you will get better results with an external headphone amp and DAC, but it will cost more than a $200 Xonar ST/STX. You could consider something like a Schiit Asgard ($250) or Valhalla ($350) headphone amp and the new Schiit Bifrost DAC ($350 - $450[usb opt]). (http://www.schiit.com) reasonably priced with reported excellent sound on these forums. IMO, also cost effective. There are many many other choices.
That said, the Xonar's are excellent consumer grade sound cards. Many owners of Asus Xonar sound cards are of the opinion that the Xonar ST (PCI card) sounds a bit better than the Xonar STX (PCIe). From reading reviews, it seems the difference may be due to the fact that the ST has better (lower) jitter numbers than the STX due to an additional chip to control clock jitter. Jitter is timing error/distortion which all DACs have to a greater or lesser degree. If you're interested, you can read more about such things here: http://thewelltemperedcomputer.com/KB/Bit1624.htm
In addition, the ST doesn't require a PCIe to PCI bridge chip. Anyway, IMO both are excellent choices and will power DT990s quite well from the front or rear headphone jack (STX). The STX was designed for headphone listening, the ST is more of an all purpose card with the option to buy an add on board for 7.1 home theater needs. The STX has no inherent 5.1 sound capabilities, it's designed to be an "audiophile" 2 channel stereo card.
If you go the Xonar route, after getting used to the stock sound, you may wish to consider experimenting with different chips in the I/V and buffer sockets to change (improve) the sound of the card from stock. It can be substantially improved. There is a large thread in this forum on tweaking the STX here: http://www.head-fi.org/forum/thread/421890/the-xonar-essence-stx-q-a-tweaking-impressions-thread
A guide here: http://www.head-fi.org/forum/thread/475872/asus-xonar-stx-st-and-headphones-a-basic-guide
The STX (and I believe the ST, too) requires a direct power connection from your computer power supply. This is to provide cleaner power for improved audio and to bypass motherboard power/noise issues. The better your computer power supply, the better results you will get with your Xonar card.
As for setup, I recommend that you don't use the Asus CD to install the software. Instead download the latest software from Asus (for the ST card running on Win7 64bit): http://support.asus.com/download.aspx?SLanguage=en&m=Xonar%20Essence%20ST&p=21&s=1&os=30&hashedid=k8OChreLuh8zgFmQ
Once you install your card and Asus driver software, go into the Asus software and set your card for 600 ohms to get the maximum power the card can deliver into DT990/600ohm headphones. The STX specs are:
Line output: 2.16V
Headphone out: 885mV ( 0dB, for headphones with impedances below 64 ohms)
3.52 V (+12dB for headphones with impedances of 64–300 ohms)
7.03 V (+18dB for headphones with impedances of >300 ohms).
Getting 5.1 from the digital out connection of the card to your Logitech speakers is not difficult. If you use Foobar2000 or J.River Media Center 16 for your software player then, for bit perfect sound, make sure to select either ASIO or WASAPI as the digital output mode in either program. If you search this forum there are several additional threads that will explain how to do this in more detail if you need it.
Buy a decent 75 ohm coax cable and connect it from the Xonar RCA S/PDIF digital out jack to your Logitech's digital input. It worked just fine on my Logitech Z-680 5.1 surround setup when I used it in the past.
Finally, the STX does not permit simulanteous headphone and speaker listening. The minute you plug in your headphones, the line out or digital out will be cut.
Edited by Rizlaw - 7/6/11 at 8:45am