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post #1561 of 1567

I also have a couple sets of those Russian tubes, actually like the sound of them and never experienced your problem.  The blue flashes are a sure sign of an incomplete vacuum.  If it's air that leaked in the getter will indeed turn white due to oxidation as Skylab said, once that happens, toss them out or serious fireworks will start.  If it's another gas in there (no idea how/why) then the getter might not actually change and apart from the flashes you might be ok. 

 

Enjoy the TS 7236, very nice tubes imo.

post #1562 of 1567

I've had a couple of tubes with the blue aurora and always thought it was caused by a excess of gas in a new tube burning off as it soon disappeared with use. If they are not making loud popping or crackling noises whilst running I would be tempted to just leave them on for a couple of days straight. If you try a google image search plenty of examples turn up see if anything matches what you are experiencing.

post #1563 of 1567
post #1564 of 1567

Very interesting Oskari.

 

I too thought it was a sign of a bad tube and I would discard it.

post #1565 of 1567

Like I said previous a faint blue glow can be normal depending on what tube and amp being used. I have seen the blue glow when the room is quite dark. A bright blue glow is not normal especially when noise is being generated at the output. A faint blue glow usually stays that way when tube is in use.

 

"All power valves will exhibit some blue glow. That's a florescent effect caused by electrons striking the ions in the inert gasses that exist within a valve's bottle (i.e. argon) as they flow from the cathode sleeve to the plate.

When the bottle starts to lose vacuum overtime, this glow may become more pronounced. On these valves the valve is said to be "gassy".


Edited by john57 - Today at 10:36 am
post #1566 of 1567

I recently purchased a 274 from Emission Labs , included in the box was an information sheet

Here is what they say about the blue light

 

"Some occasional blue glow effects will disappear during burn-in , or may stay. This is not gas, and it is normal."

 

As one of the last tube makers left I think you can trust their word

 

My own experience follows this advice , sometimes it goes away sometimes it stays but it has never been a problem

Noise is similar often it will fade away with use , generally I will give a noisy tube 100 hours and if it persists it is destroyed 

The only condition I will not tolerate in a functional tube is the arc , that is a bright blue or white flash quite violent in nature and often accompanied by a loud crack . I believe this condition to signal imminent failure by dead short which can cause serious damage and is best avoided

post #1567 of 1567
Quote:
Originally Posted by john57 View Post
 

I wonder if the seller send you a box of marginal tubes. I never had any issues with the Russian tubes like that. What I do not like is tubes that pop.

 

 

Quote:
Originally Posted by john57 View Post
 

Like I said previous a faint blue glow can be normal depending on what tube and amp being used. I have seen the blue glow when the room is quite dark. A bright blue glow is not normal especially when noise is being generated at the output. A faint blue glow usually stays that way when tube is in use.

 

"All power valves will exhibit some blue glow. That's a florescent effect caused by electrons striking the ions in the inert gasses that exist within a valve's bottle (i.e. argon) as they flow from the cathode sleeve to the plate.

When the bottle starts to lose vacuum overtime, this glow may become more pronounced. On these valves the valve is said to be "gassy".

 

Well I think you a right. I think I got sold a box of reject tubes or seconds.

 

Update: I decided last night to continue to roll all 12 tubes that I had to see if I could find some good ones.

The two I had in were fairly bad. Both flicker blue. Both have a lot of noise. So they were out.

The next two produced one terrible and one perfect. The perfect had zero blue glow and zero noise. I was happy with that one it gave me a reference.

From there I started changing one at a time. Disastrous, one after the other was terrible. Some were like laser light shows. Flickering electric blue everywhere. Noise through the cans was awful. Hum from the Woo as well. I had four tubes to go and I was almost reduced to tears. It just sounded that bad. So out of 8 I got 1 good tube. No good to me as I need 2.

So I thought stuff this throw in my Brimar 6080 power tubes. F#ck these were terrible as well. No blue glow but the popping and noise through the cans was extreme. By this stage I started wondering if there was something wrong with the Woo???

Lastly I stuck my TS 7236 tubes in and I thought I could hear noise but I was getting worn out and thought it must be placebo. When I say noise nothing like the other tubes. I think my ears had gone and I was just hearing things. So I went to bed exhausted.

Got up this morning and fired it up with the TS 7236 tubes and they are dead silent.

 

I have no faith in the Russian tube. Really think I got sold rubbish. So I will toss them away. Brimar is no better so they will get tossed as well. Nervously that only leaves me one set of power tubes. From now I think I will just by the TS 7236 tubes from Woo. Or someone else said the TS 5998 is nice as well.

 

Picture below of the glow effect. Best I could capture. More intense by eye.

 


Edited by Badas - Today at 3:28 pm
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