12AX7 tube comparisonⅢ / Very close but slightly different.

My 12AX7 of SIEMENS and PHILIPS.
Are these relabel of Ei?

GE 7025 and RCA 5751 are reference ultra high quality sound.

GE 7025: ultra high quality reference sound 0:10 0:40
Ei: little stimulus 1:10 1:40
SIEMENS: rather stimulus 2:10 2:40
PHILIPS: not so stimulus 3:10 3:40
RCA 5751 : smooth reference sound 4:10 4:40

their shapes are very close but sounds slightly different.


signal chain:
PC DSD~FOSTEX HP-A8 USB DAC~12AX7 SRPP~EL34 triode connection~scanspeak lumine~tascam dr-7~youtube