Usually if the unit doesn't sound OK with stock tubes and "needs" NOS it is poorly engineered unit. It's the same thing as I could say that I can play soccer good in Adidas boots but cannot play with Nike.
Stand-by current is good enough for tubes. On the new tubes it is essential to idle the amps even overnight and than start listening. Further-on idle the small signal tubes for 10...20 minutes before passing any signal and before every listening.
Aso try to damp your tubes with the tube dampers to see the result. Placement of your tube preamp maybe essential as well. Make sure it's not located above the power amplifier and mates only with small signal components.
IMO I love for the small signal SS and drive speakers with tubes. That's where you get passive-like transperency in the small signal and the signature of a tube drive.
You might also try Plinius M16 preamp with powerful tube amps such as VTL MB450, VTL MB250, Manley Reference 250 or ARC VT200 that will drive your speakers at ease.
Stand-by current is good enough for tubes. On the new tubes it is essential to idle the amps even overnight and than start listening. Further-on idle the small signal tubes for 10...20 minutes before passing any signal and before every listening.
Aso try to damp your tubes with the tube dampers to see the result. Placement of your tube preamp maybe essential as well. Make sure it's not located above the power amplifier and mates only with small signal components.
IMO I love for the small signal SS and drive speakers with tubes. That's where you get passive-like transperency in the small signal and the signature of a tube drive.
You might also try Plinius M16 preamp with powerful tube amps such as VTL MB450, VTL MB250, Manley Reference 250 or ARC VT200 that will drive your speakers at ease.