Hi
Since USB audio interfaces give noise when recording in my particular set up and firewire interfaces are clean as a whistle I wish Steinberg sells a firewire audio interface soon again. 
I’m looking into getting a used mr816csx since I want to keep my setup Yamaha Steinberg where possible.
Very sneakily a crossgrade to ProTools entered my mind as well…
Not all USB interfaces will give you noise.
I tried three USB audio interfaces to reasonably eliminate a single usb interface was the problem. All had the same sounding noise while recording. My firewire interface that’s over 10 years old works flawlessly.
I’m using a USB interface and it doesn’t give me any kind of noise that’s not intended. Maybe it’s something with your system or you have some sort of ground loop problem that start to become obvious when using a USB interface?
Yes, I suspect an issue with my set up, I tried numerous things even placing a jitterbug (which actually added noise on top) when recording with my Yamaha keyboard.
Removing my video card resolved the issue for audio playback, but when recording I still had the same noise.
I pretty much gave up and can solve it by just placing a firewire audio interface.
Update:
I’ve bought a UR12 for my laptop, it worked great. Just by a long shot I decided to hook it up to my pc and it worked without the annoying interference. I was surprised as two other USB audio interfaces gave problems including the one from the Yamaha MX88 keyboard.
I will soon try the unthinkable and see if it will even function with the dedicated video card inserted, how times and perception change. I’ll let everyone know how that plays out.
By the way, Steinbergs USB sound cards are sturdy as a rock and great sounding with an acceptable noise floor. Great quality for the price!