Tube Flair on start up

Entropyman · 836

0 Members and 2 Guests are viewing this topic.

Offline Entropyman

  • Newbie
  • *
    • Posts: 5
on: December 22, 2018, 08:42:21 AM
I managed to replace a bad capacitor in a tube integrated amp I have, but have noticed in the past that the 6SL7 on the left channel flairs (visually, there is an increase in the brightness of the tubed a bit on start up, then calms down after a second or so).  The left channel is also the one that seems to have the shorter tube life, and is a bit louder than the right channel.  Any possibility those issues are connected? The bad cap was also left channel......

Any insights would be appreciated.

Phill



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19696
Reply #1 on: December 22, 2018, 08:59:09 AM
The glowy bits are the heaters in the tube, and they will tend to draw a bit of extra current on startup.  You can read up online about the "Mullard flash" that's associated with 9 pin Mullard tubes that flash when first turned on.  There's nothing wrong with any of this.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man