Perceived SQ differences playing local files

[Jandu]

A new moOde user here and a pretty happy one so far!
I run it on a RPi4 with Pi2AES.
Based purely on SQ, I prefer moOde to Volumio.

I do not use streaming services as I prefer playing local files for reasons of availability (my strange music taste) and SQ. So I did some listening tests, playing from:

(1) pc (JRiver or UPplay) to pi2aes UPnP
(2) nas
(3) usb drive connected to the pi2aes with a 15m fiber based usb cable
(4) local usb drive
(5) sd card (the same one containing the os)

The perceived SQ increased from (1) to (5).

Therefore....

Suggestion:
Try a CF(compact flash) card USB reader and use the CF card as music storage. I find that storage medium gives the best SQ. 
I do expect to see a few responses saying that bit is bit and there should not be any differences.