[Captainhemo]

Happy New Year to  everyone..

Does the amount one of these tubes flash when energized vary quite a bit from tube to tube ?  I picked up a clsely matched pairof Amperex ECC83's ('62, 165 series,  Heerlen factory)  and they do sound  great but  one flashed very brightly at  startup while the other  is a much dimmer flash.  .
Was wondering what you guys have experienced  with regards to this ?

-jay

[Freo-1]

Normal behavior for Mullard/Amperex 12AX7 tubes. 

[Captainhemo]

Hey Freo

I knew the flash was normal,  just wanted to make sure  it was  "normal" for one to flash birghtly while the other is much dimmer,  guess they all vary to a degree

-jay

[Freo-1]

Yep, no worries.  They are very likely fine.  It is normal to have them behave differently.  Some will flash a lot, while others will show very little. 

[Octadyn]

I bought 2 matched pairs of Gec CV6091's and only 1 tube has a bright flash on power up but the other 3 don't flash at all. I also have a pair of Amprex Bugle Boys where 1 flashes brighter than the other but I also believe these are rebranded RFT's.

Bottom line is it's nothing to worry about 

[shoot]

needn't worry about it,It calls flash filament,in order to heat faster.