The blue glow, is this bad? I noticed the rectifier emitting a blue glow seconds after power up. The blue glow disappears after some time.
I did change the tube rectifier. The new one doest not emit the blue glow. Is the old rectifier defective?
Regards.
Louie
It has occured that the sudden flash of blue glow is caused either by the sudden demand of current and a fairly large input capacitor. Several of my specimens confirms that the input capacitor used was much too big (100uf) for the rectifier used (which should be about 40uf only), hence the blue glow. I believe this problem has been addressed already in their recent models.
To answer the question; your old tube rectifier may not necessarily be defective, it's just that the tube is exposed to repeated stress while the new rectifier is more stronger, it can handle the sudden load.
One solution I gave these users of those amps is to "manually bypass" this switch. What I mean is if your stand-by switch is part of a selector switch which is also used for the power-on, then instead of stopping at the stand-by position, immediately switch to power-on position. However, this may not be a solution if your input cap is off spec.
With a large, off specification input cap, your tube rectifier is bound to die sooner than is expected.
Best Regards,
JojoD