Do tubes wear out faster if they light up brightly or flash when switched on?

A frequently observed phenomenon is the brief, bright flash of the heater filament immediately after switching on the device.

The cause: This behavior is due to the so-called cold resistance of the heater filament. If this resistance is particularly low in the cold state in a specific tube, a very high switch-on current flows at the first moment, causing the filament to glow brightly for a short time.

Assessment: Long-term experience over several decades shows that this glow is completely harmless for the tube. It is a harmless physical property of the heater filaments and has no effect on the longevity of the component.