Pci-e usb card and clean power to dac

[sbronf]

Hello, I would like an opinion from those who are more experienced or who perhaps have been able to measure.
I bought one of those usb cards on pic-e slot, where each port has its own power supply section (at least that's how I understood). I wanted to understand if this card can give a cleaner current to the dac than those of the motherboard or it's not worth thinking about. thank you very much.

 

[unpluggged]

Which specific problem are you trying to solve? Does your DAC have faulty power supply?

 

[sbronf]

Hi, no problems, i speak in absolute terms…

 

[DVDdoug]

Computer power tends to be noisy but DACs and USB soundcards have some filtering and (audible) noise in the audio isn't that common. Digitial is immune to this noise (or else your computer would have all kinds of corruption and crashes) but sometimes it leaks into the analog circuitry. Of course a DAC with it's own power supply eliminates this possibility.

...Once, I tried to power some computer speakers from the computer's internal 12V power supply (because I was missing the power supply) but I got a loud screeching sound. My "smart idea" failed and I had to buy a power supply.

Noisy USB power tends to cause more problems for an audio interface with microphone inputs because the high-gain amplifies any noise that leaks into the microphone preamp.

Some quick research says that the PCIe bus has 12V available. Regulating that down to 5V for the USB bus could allow for some excellent filtering. If they are doing that, it could be a good thing! But since computers also have 5V internally so the card manufacturer would only add the extra circuitry if it's specifically designed for USB audio.

 

[khensu]

If that PCIe card couldn't manage the voltage properly, you'd have all sorts of problems with it, not just with audio. If the USB ports are working correctly, you're fine for audio.

 

[Dunring]

I was able to get a silent noise floor on a gaming computer using a Febsmart 2 port USB card. I faced the power supply fan down since the case had vents for it, and elevated it in some rubber door stops glued to the bottom for airflow. The heavy shielded side of the power supply helped, and located the card at the bottom slot to get it away from the video card.
I also use a Topping d30pro/a30pro which have 3 prong power connectors. Using DACs that just get power from USB can be hit or miss for noise floor.