by Geek » Sat Sep 26, 2009 2:17 pm
Hi,
For new tubes, I bias them initially, then after ten minutes and finally after an hour.
If there's more than a 10% variation with older tubes, they may need replacing (heats up things expand, grid distances and cathode emission change, too much may be real bad for the power or OPT)
Some brands (Philips are terrible for this) need a 24 hour burn-in if they've sat for a long time.
Cheers!
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.