Actually maybe to test this even better would be to play the CD from a computer optical drive into your sound system vs a freshly ripped flac played in the same audio software to your sound system (play the CD in foobar/play the FLAC in foobar)I didn't rip these flacs myself. I should rip one and compare. Signal path is the same.
This would remove the potential superior nature of the DAC inside a consumer CD audio deck (if you are playing in one of those) and make the signal path even more aligned for your test.
Bonus points: get a friend to blind you and not tell you which one he is playing
Bonus Bonus Points: get more friends to do it and blind THEM so it's not even just you doing the judging