I got an overkill PSU for my PC leaving me so much watts unused, so it would be best to use it from there. I'm planning to connect the out to my soundbar and mix it with other inputs like a phone or DVD player
I take it you never have experienced microphone feedback. Not even talking your computer just audio it can fry a tweeter, blow out the spider in a woofer. Take a channel out in an amplifier in an instance.
You use your computers power supply while pc and mixer and everything you plug in and use your opening it up to a quick death, static and ground issues. That whole ground yourself before you work on computer parts is out the window with the roll of the dice.
I commend you for thinking out side the box but as hardy as our Pc's are sometimes you here , my computer was working fine and all I did was blow it out and now it's dead.
If you were here to ask can I use a computers power supply on the bench to test a car radio that's a whole different outcome
Why are you choosing to make the most complicated thing possible to solve a problem that can be solved by a high end sound card Internal or external. If this thing will always be "on" only with the PC, then why not use the giant expensive box that can do all this that you already have.
Internal card with the applications and inputs you want:
The Sound Blaster GC7 is the first in its series of premium gaming audio solutions for experienced gamers, content creators, and streamers. Packed with both Super X-Fi and Sound Blaster audio technologies, the GC7 offers more than just audiophile-grade audio. Enjoy quick and fully customizable...
Pick one, buy it, plug it in, install software, Profit.