Hmmm. Caveats/Disclaimers upfront-- I don't have decent headphones available right now, and I'm listening to these examples on some cheap 1-inch "Leading Edge" speakers, so YMMV.
BUT... I don't really hear any "noise" or "hum." They may be there on closer inspection, just saying I can't track it right now. What I am hearing on the raw piano, and especially the raw guitar track (and the "noise reduced" one as well), is what I'm pretty sure is clipping/digital distortion. Do you hear how the piano track (both versions) completely cuts out at about 00:11 secs., and there's that little "burp" (glitch) at 00:17 and again at 00:20? That sounds like you blew out the condenser mike a little bit there. Where are you placing the microphone? What input level shows when you look at your meters? What does the file look like? (Is there a big volume "spike" at the previously mentioned second marks?). I think you're over-driving the condenser element, which is pretty easy to do. Mike placement on guitar and piano are very important. Did you put the microphone directly in front of the sound hole? (a big recording "no-no," generally speaking). The raw piano also seems to be clipping on the left side of my stereo image.
Check out some tutorials on live recording and mike placement, back-off the input level a bit, and see if that helps. If there's still an issue or issues, post again and we'll re-evaluate. I will also try to listen to the samples on a better system and/or with headphones at some point; I'm not hearing what Krushing and ponkapog hear if there is hum there, it's quite possible. But the other problems I mentioned are more egregious, IMHO. Also, the guitars a bit out-of-tune, bruh. The usual suspects? A string, B string, and/or high E; check it out again and/or use an electronic tuner.
BTW-- "noise reduction techniques are really just for use in desperation"-- Absolutely correct! Getting a good recording of the source sound, with good microphone placement, no clipping or distortion, plenty of volume (but not too much!) are where it's at; 90-99.9 percent of recording issues can be tackled there. Next would be inspecting your signal chain for any real "noise." Then of course, room treatment. After those are taken care of, you will probably almost never have any issues with your raw tracks. Once we start looking at noise reduction or noise gating, we are travelling down a deep dark hole of never-ending tweaking, and never really being satisfied with the sound anyway. Don't try to "fix it in the mix," get it right at the source!
GJ