Hier ist die Kern der Sache. Ich habe kein Zweifel du konntest ein Unterschied hoeren, wenn du die Tubes A/B vergleichen konnte.
"High number will have to be driven at higher volume levels to begin to reach output stage distortion. These are liked
by some Jazz players that want a very clean sound. They are also preferred by some heavy metal folks, who want
very clean high headroom. These folks like to get most of their distortion from front end effects, pedals, or by
running their preamp levels very high. These tubes have the least dynamic touch and will give the most clean
headroom. These are the GT 8-10 range, and the Fender "red" painted tubes.
...
In a amp with a given bias, a higher GT rated tube will have a higher idle dissipation if no adjustments are made.
This aspect can be used to fine tune amps such as older tweed era Fender amps, Mesa Boogie Amps, Hiwatt,
Orange, etc. If you find as an example that a #5 tube has an idle of 26mA and you wish something closer to 30mA
you may want to try a #7 rating. "
steven