Have you ever used tubes in the past? I imagine the answer is no. While you may be able to detect a difference between each tube used and you should considering all the different tubes your using i.e. 12at7, 6dj8,12au7, etc. My first question is. Where did you purchase you NOS tubes? Some of the ink makes me think you may not have the real deal. 2nd. Are the tubes New (never been used)
Tubes take about 100 hrs of playing time to be properly evaluated especially many of your NOS tubes like Amperes, Radiotechnique, Mullards, Phillips of holland. It takes any tube 3 minutes to warm up so your evaluations at 10 minutes , or 30 minutes if they were new will not reveal the true nature of the tube. Hopefully that tube is actually being used in that configuration. Bravo makes a headphone amp that uses a tube, but the tube really has no impact. Good luck
Paulc