No blue glow from 2A3 tube ??

[rolf kwist]

Hi, I've just got a Melody H2A amp with 4 x 2A3 tubes. This is a 18W class AB1 amp. When operating only three of the tubes give the nice blue glow and one is not. The wire on the top of the lamp is burning though, so it's not completely "dead".

To my opinion, it doesn't affect the sound; but I'm only new to tube land...

Does any one know what could be the problem?

thanks!
Rolf

[Vinni]

I think the not blue glowing tube is the tube which is 100% okay.
But the blue ones are okay, too.
The blue glow is produced through rests of gas in the tubes, it doesn't effect the sound, but it is nice to see, isn't it?


So don't worry...everything is right

Vince

[GlowingTube]

Hi Rolf,

I understand your posting, that it doesn't matter which of the 4 tubes is been removed for having the blue glow? Any 3 tube will give the nice shining, correct?

I guess, the blue glow is also a function of the anode voltage. With all four tubes lugged in, the anode voltage should be a little lower and due to this the blue glow disappears?

Sure, it's nice to see this gas discharge but has nothing to do with the sound quality at all.

Best Regards,
Rainer

[dissa99]

I would say buy new valves , blueing is a sign of valves on the way to heaven , which is why certain companies sell their valves with lovely blue glass !!!!!!

[Tom_H]

...blueing is a sign of valves on the way to heaven.....

that's similar to normal operation. Any hour brings the tube closer to death...........

Sorry, I couldn't resist........

[GlowingTube]

I would say buy new valves , blueing is a sign of valves on the way to heaven , which is why certain companies sell their valves with lovely blue glass !!!!!!

Hello dissa99 (sorry, I can't find your real name),

does this mean, that I shall throw my currently new bought SED6550 away???

[IMG:150:128]http://img112.imageshack.us/img112/2638 ... wa6.th.jpg[/img] [IMG:150:128]http://img329.imageshack.us/img329/4840 ... qz7.th.jpg[/img] [IMG:150:128]http://img165.imageshack.us/img165/5581 ... id8.th.jpg[/img] [IMG:150:128]http://img165.imageshack.us/img165/1986 ... ro0.th.jpg[/img] [IMG:90:165]http://img102.imageshack.us/img102/8427 ... kn2.th.jpg[/img]

All pictures have been made with an aperture time of 15" !

Regards,
Rainer

[DB]

Hallo,

to your question:
Royal-Blue glowing (looks like Cherenkov-Radiation in an atomic reactor): Valve is okay.

Violet glowing: Valve contains remainders of gas.

Best Regards

DB