[whatthefunk]

I have a pair of NOS tubes in which only 1 of the tubes does this. When i first turn the amp on it flares up very brightly near the bottom of the tube for about 1 second... after that initial burst and once warmed up it sounds fine. Is this indicative of a faulty tube? Is it safe to continue using it?

 

[Nick 214]

From what you're describing I'd say it's just a case of tube flash. No worries if it normalizes soon after. One of my Telefunken 12AX7s does it every time I start the preamp.

NK

 

[whatthefunk]

Thanks NK! I had no idea it was called "tube flash" so that's very helpful.