Nos amperex/Philips tube lights up
 

I did find 4 matched Nos philips/amperex holland made fom 1963 - 1969 here in sweden to a really good price so i brought them and just put them in.

But when i start the pre amp (C500T) the tubes flashes like a normal light bulb for 1 sec and then turn green. is this normal? It did not do this with the gold lions.
Everyting else is normal

Your tubes are fine. Older 12AX7 variants made by Phillips or under license from them exhibit this effect - a bright filament on startup and then dimming down to normal as the tube warms up.

Newer 12AX7A tubes have a more controlled startup and don’t exhibit this behavior. The A suffix stands for controlled filament warmup.

Tom

Ok thank you!