There are many claims about improving the sound quality by tuning the computer hardware.
Storing the data on a NAS is one of them.
Like all of them, they are not backed up by any measurement.
Take them with a grain of salt.
My opinion (not backed up by any measurement either
), if you use an outboard DAC, the AD conversion is not exposed to the electrical “noise” inside a PC.
There are a lot of DACs today with asynchronous USB and some kind of galvanic isolation on sale. I do consider them reasonably shielded from the “noise” generated by the PC.
A NAS is a relative expensive solution.
If the collection fits on your PC, all you need is an outboard HD for the backup.
A lot of routers do allow for an outboard HD. If this is the case you do have your “NAS”.
25 feet I don’t consider “long”, probably a well shielded RCA will do the job
If you go the USB DAC way, you might fool around a little, long USB (5 m max) / short RCA and the opposite.
As you budget is limited, there are small USB DACs within the budget getting positive reviews like Meridian explorer, .LH labs Geek, iFi iDac, Firestone, iBasso, AMI Musik, etc.
AIFF is a popular format most of all on the Mac. It is the Apple equivalent of WAV.
I recommend FLAC
• Lossless
• Excellent tagging support including cover art
• Allows storing custom tags in the file
• Checksum stored in the file. This allows you to verify if the audio is corrupted
• Wide support on Win, OSX, Linux, Android
Guides: there is a lot of information in the WiKi.
Maybe my website is of use:
http://thewelltemperedcomputer.com/SW/Players/MC14/MC14_intro.htm