I'm planning to buy a new soundcard, but I was wondering: is there anything negative about USB soundcards, compared to internal PCI Express soundcards?

I'm thinking about buying an Asus Xonar D2 card. The only reason I would chose a USB soundcard is because it's easy to connect on different computers and maybe it's a bit more "future proof"? I mean, what will the future be of PCI Express? Maybe there will be a new standard in a couple of years, so if you buy a new computer than, you'll have to buy a new soundcard too?

What do you guys think? Is USB as good as an internal card? And which USB card do you recommend? I need a good soundcard to connect digitally to my receiver.

(Sorry if my English isn't really good... I'm trying... )

If the USB box needs an external power supply then make sure it's a good one.

There's nothing inherent in USB sound cards that make them worse or better than PCI Express sound cards. Personally, I think a USB sound card offers better isolation from the electrical interference inside your PC's case.

What is going to make the biggest difference are the components the sound card is made of, whether it's PCI or USB. Look at specifications, look at price and read some discussion on Hydrogen Audio when you are getting ready to settle on a specific card.

Hope that helps.

This is one of the reasons I went USB. I used to get terrible interference from the CPU and graphics card with my onboard sound - however I'm not sure how much of that intereference would still be there using a PCI or PCI-E card, so I have no real evidence to prove USB is better in this regard.

I find having my inputs and outputs on my desk (rather than on the PC on the floor, and also RCA inputs/outputs) a great advantage from an accessibility point of view, especially regarding headphone output - the Edirol UA-1EX I have has a dedicated headphone volume control too which has made things a lot easier when switching between them and my hi-fi.

Decent PCI cards suffer from no interference of this kind, it's a feature of onboards, likely not all of them. I went with USB though (M-Audio FastTrack Pro) but the reason was to have a volume knob (actually two, for monitors and headphones) and a headphone output. PCI cards are probably less prone to dropouts, but this should not be a problem on a good system. Smaller latency, if you care, should be achievable with PCI than with USB.

I switched to a USB sound card for a different reason. When I used the onboard sound card in my computer, I was getting dropped frames while capturing video. When I switched to a USB sound card the problem went away.

Hm, seems like a lot people are using a USB sound card. And I don't read anything negative about it. I guess it's time to look around for a good USB alternative for me. :-)

That's a good point and I certainly didn't mean to imply that even a half-way decent PCI sound card will suffer from interference. If it comes in at 100dB S/N or better, the manufacturer has done a good job of mitigating these problems.

And yes, soundcards built-in to the motherboad are far more susceptible to interference. Further, they are often made with cheap components to keep the overall cost of the motherboard down. Beware of the integrated sound card!

As noted already it is all relative to components quality and how well they are integrated. USB devices are limited in power as the bus can only supply limited current. So anything more capable requires extra PSU but then the quality issue pops up again.
My understanding is that PCI/PCI-e cards are the best followed by firewire, usb and onboard audio at the very end.

pci /pci-e sound cards > usb sound cards > onboard audio

(firewire cards usually rank between pci/pci-e and usb)

My experience is that when it comes to perceived sound quality, PCI soundcards are indistinguishable from USB soundcards - I don't think I could tell the difference between my FastTrack Pro and M-Audio Audiophile 192. Onboard audio cards I had experience with were at completely different level. Much lower.

USB cards may be more prone to hiccups and dropouts than FW or PCI because the very design of the USB interface is not well suited for audio. But this can be an issue on old/badly configured systems.

And you are also not right about the power requirements. When being used as DACs, soundcards send line-out signals to high impedance amplifier outputs, thus they have to produce almost no current. So unless you need a huge number of outputs and inputs, or your USB card is ancient/poorly designed, you don't need a PSU. For my card the USB port capabilities as current source are good enough to supply Phantom Power and drive headphones in addition to driving line-outs.