ivyanev :
While great article it misses some details in using the cheap onboar sound card - background noise- when volume is high and no music is playing there is a lot of humming. In fact it is so loud it can be heared when there is very quiet song with volume of the software player dialed back a bit. Not to mentioned i had sound card (integrated) in which i could hear clicks from the headphones when i scroll the mouse wheel. I currently use external usb sound card from creative, and there is noticable difference.
mnl2g :
I noticed a big difference moving from a Realtek chip to an external DAC/amplifier, mainly because it was just much less noisy. After reading this article I'm inclined to think this is more likely due to jitter in my power-supply than the Realtek chip itself - the noise would change frequency if I alt-tabbed between my desktop and a game for example.I also would like to point out that the comment about cable transparency is a little misleading too. I have a 20ft el-cheapo cable which is anything but transparent! It sounded so horrible I nearly threw it away. I still have it, if you like I can record an A/B of it for you (through my 24/96 interface, where it actually matters). That's not saying I'm vouching for those ridiculous boutique cables, but really crap cables can make a noticeable difference.Also when it comes to unbalanced signals (e.g. electric guitar), cables will make a marked difference (diminishing returns still kicks in pretty early though).
I have a specific answer to this. The noise you are picking up is due to the Switch Mode Power supply.
My Setup is thus:
I use an EMU 1212M with balanced connections to my amp.
I have a Rosewill 350 Watt Silent PSU
I have a combination of Tripplite 10 AMP 12v Linear Regulated supply and a DC to DC ATX converter.
The DC to DC ATX converter does do switching, but I think the 12v rail isn't switch mode, just inverted and filtered. The 5 and 3.3 are switched. So it isn't 120V switched down to 12/5/3.3 for starters.
The EMU has the ability to switch ananlog I/O between Balanced and Single ended.
As a test I took some well constructed bulk MIC cable and built TRS to XLR unbalanced on purpose. I left the ground floating at the XLR end of things. Switched the card to Single ended mode.
I put in the Rosewill power supply. You could hear mouse movement and HD access (if a mechanical HD, SSD was silent in this regard).
With same Rosewill supply I used balanced TRS to XLR and set the EMU to balanced output. Balanced connections did what they do best: They rejected the noise.
Now onto the Tripplite and DC to DC ATX converter:
I placed the unbalanced TRS to XLR back in the chain. I bring up my other single ended configuration on the EMU 1212M and NO NOISE. Couldn't hear the mouse, Couldn't hear mechanicals of the the spinner hard disk.
So for ~$100 I managed to get rid of the largest single complaint about computer audio: EMI from the PSU.
I run with the Tripplite and DC/DC ATX and balanced connections. My noise floor with a Crown XLS 1500 is ink black. At system idle you don't even know the amp is on.
My speakers are DIY Curt Cambell/Jim Holtz Statements for anyone that would like to look them up.
Interesting tidbit: When I was running Parasound HCA1000A (two in mono-block) there was tweeter hiss. I switched from an "Audiophile" amp to a "Pro-audio" amp and couldn't be happier.