diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Tubes / Valves (http://www.diyaudio.com/forums/tubes-valves/)
-   -   Is this ok (http://www.diyaudio.com/forums/tubes-valves/174844-ok.html)

tofts 5th October 2010 05:58 PM

Is this ok
 
Was taking some HQ long exposures of my RM100.

Noticed a blue glow, I think this is ok, but I thought I would double check.

I know in some cases it could mean they need rebias/replacing

http://www.dragonsbloodtribe.co.uk/i.../valve1024.jpg
Ultra HQ Version of Above

http://www.dragonsbloodtribe.co.uk/i...valves1024.jpg
Ultra HQ Version of Above

Thanks,

Jody

piano3 5th October 2010 06:13 PM

Is the getter nearly gone?-that is,I think, when I have seen this.

Mooly 5th October 2010 06:13 PM

Can you see the blue by eye in the dark ? or just on a long camera exposure.

athos56 5th October 2010 06:19 PM

I've read that the 6l6s glow like this, AFAIK it is ok.

tofts 5th October 2010 06:22 PM

Yes, you can see it if its pitch black. But not evident with lights on.

HollowState 5th October 2010 06:28 PM

Quote:

Originally Posted by tofts (Post 2323516)
Noticed a blue glow, I think this is ok, but I thought I would double check.

A little blue glow on the inside of the glass envelope is quite normal for output tubes. It's caused by residual outgas from the metal elements being bombarded. Nothing much to be concerned with. A blue haze or glow inside the plate structure would be cause for concern. But this is not the case here.

Mooly 5th October 2010 06:33 PM

Quote:

Originally Posted by tofts (Post 2323539)
Yes, you can see it if its pitch black. But not evident with lights on.

I think it's probably OK too.

tofts 5th October 2010 06:44 PM

Just another quick query, I have been told that I could use other types of valves when I come to replace these ones. I know the KT66 has the same pins as the 6L6, but what other valves would offer similar specs?

Presumably I could drop them in, rebias and off I go. So long as the replacement valve are similar in specification. I know heater current draw can be vastly different, but judging by the shear size of the power transformer I don't think it should be an issue.

M Gregg 5th October 2010 06:52 PM

Quote:

Originally Posted by tofts (Post 2323516)
Was taking some HQ long exposures of my RM100.

Noticed a blue glow, I think this is ok, but I thought I would double check.

I know in some cases it could mean they need rebias/replacing


Thanks,

Jody

Just for interest here is a link!:)

Wapedia - Wiki: Vacuum tube.

Regards
M. Gregg

M Gregg 5th October 2010 06:57 PM

I think it is O.K.

Is the amp auto bias or fixed bias?


All times are GMT. The time now is 06:44 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2