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Old 07-03-2016, 11:09 PM
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esteban esteban is offline
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Default Is this normal?

These photos are of a brand new quad of Shuguang EL-34 B's. They probably have less than 40 hours on them. Please excuse my ignorance (I am a tube noob), but I just noticed something that I do not think I had seen before. It may or may not be perfectly normal. What do you make of the following:

This is how they look with normal lighting:





And this is how they look in the dark (please excuse the soft focus... I had no time to play with the tripod position):





Notice that the top area seems to be "faded/fading". The upper area/coating is darker in the center of the tube's top (above the getters), but considerably lighter on the sides/edges. The color is basically a light gray, but not white (I believe that would be a sure sign of trouble). The tubes look perfectly fine (at least to my untrained eye) otherwise, and there are no audible issues as far as I can tell.

Is this normal? Or did I get a bad quad?
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Old 07-03-2016, 11:16 PM
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Here is another photo. Hope I am able to illustrate my dilemma properly:

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Old 07-03-2016, 11:35 PM
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Esteban.......The color of the getter deposit and its density are a product of barium atoms evaporating and absorbing any remaining gas in a tube once the vacuum has been sealed and flashed. You will see silver getters and even black getters depending on how fast flashing is done. That the getter deposit may be less dense on one tube than another or less dense in an area around the inside top of a tube than another area is not an indicator of a problem. If the silver, grey or black colored getter changes color to white you have a gas leak and the tube needs to be replaced immediately. Other than that, I would not be concerned about how the tube appears in the dark. If you are in doubt as to the electrical performance of a tube have it tested for gas, shorts, plate current, and transconductance.
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STUDIO - McIntosh C1000C/P, MC2301 (2), MR88, Aurender N10, Esoteric K-01X, Shunyata Sigma spdif digital cable, Sonos Connect, PurePower 2000, Stillpoints, Furutech Flux 50, Michell Gyro SE, Michell HR Power Supply, SME 309, Ortofon Cadenza Black, Wireworld, Sonus faber Amati Anniversario
LIVING ROOM - McIntosh C2300, MC75 (2), MR85, Magnum Dynalab 205, Simaudio MOON Neo 260D-T, Schiit Audio Yggdrasil, Aurender N100H, Shunyata Sigma USB cable, Micro Seiki DD40, Ortofon Cadenza Blue, Nakamichi BX-300, Sony 60ES DAT, PS Audio P10, Furutech Flux 50, Sonos Connect, Stillpoints, Wireworld, Kimber, PMC EB1i, JL Audio f113
VINTAGE - McIntosh MA230, Tandberg 3011A tuner, Olive 04HD, Sony DTC-59ES DAT, McIntosh 4300V, JBL 4312A
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Old 07-04-2016, 08:40 PM
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Dan, thank you very much for the detailed answer and explanation. I appreciate the expert feedback. Makes me feel much better about my purchase!
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Old 07-04-2016, 09:53 PM
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Esteban.......You are welcome. The real question is, how do the Shuguang EL-34 B tubes sound? Are they powerful enough for your Sonus faber Elpisa Red's?
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STUDIO - McIntosh C1000C/P, MC2301 (2), MR88, Aurender N10, Esoteric K-01X, Shunyata Sigma spdif digital cable, Sonos Connect, PurePower 2000, Stillpoints, Furutech Flux 50, Michell Gyro SE, Michell HR Power Supply, SME 309, Ortofon Cadenza Black, Wireworld, Sonus faber Amati Anniversario
LIVING ROOM - McIntosh C2300, MC75 (2), MR85, Magnum Dynalab 205, Simaudio MOON Neo 260D-T, Schiit Audio Yggdrasil, Aurender N100H, Shunyata Sigma USB cable, Micro Seiki DD40, Ortofon Cadenza Blue, Nakamichi BX-300, Sony 60ES DAT, PS Audio P10, Furutech Flux 50, Sonos Connect, Stillpoints, Wireworld, Kimber, PMC EB1i, JL Audio f113
VINTAGE - McIntosh MA230, Tandberg 3011A tuner, Olive 04HD, Sony DTC-59ES DAT, McIntosh 4300V, JBL 4312A

Last edited by jdandy; 07-05-2016 at 12:55 AM.
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  #6  
Old 07-05-2016, 12:03 AM
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Quote:
Originally Posted by jdandy View Post
Esteban.......The color of the getter deposit and its density are a product of barium atoms evaporating and absorbing any remaining gas in a tube once the vacuum has been sealed and flashed. . . . .
It's amazing that you know this!
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Old 07-05-2016, 02:59 PM
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Quote:
Originally Posted by GaryProtein View Post
It's amazing that you know this!
Doesn't everybody???
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  #8  
Old 07-05-2016, 04:52 PM
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After owning tube equipment since the late 1960's, up and through the tube gear I presently enjoy, I have learned a few things about tubes along the way. Vaccum tubes have piqued my curiosity for many years. How they work, how they are manufactured, and what makes one tube superior to another has provided countless hours of reading and research through the years. Some of the information has stuck in my brain and is easily recalled. Some other needs for information will cause me to go digging for answers. Either way, I find vacuum tubes to be interesting and enjoy listening to well designed tube amplifiers running high quality tubes.
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STUDIO - McIntosh C1000C/P, MC2301 (2), MR88, Aurender N10, Esoteric K-01X, Shunyata Sigma spdif digital cable, Sonos Connect, PurePower 2000, Stillpoints, Furutech Flux 50, Michell Gyro SE, Michell HR Power Supply, SME 309, Ortofon Cadenza Black, Wireworld, Sonus faber Amati Anniversario
LIVING ROOM - McIntosh C2300, MC75 (2), MR85, Magnum Dynalab 205, Simaudio MOON Neo 260D-T, Schiit Audio Yggdrasil, Aurender N100H, Shunyata Sigma USB cable, Micro Seiki DD40, Ortofon Cadenza Blue, Nakamichi BX-300, Sony 60ES DAT, PS Audio P10, Furutech Flux 50, Sonos Connect, Stillpoints, Wireworld, Kimber, PMC EB1i, JL Audio f113
VINTAGE - McIntosh MA230, Tandberg 3011A tuner, Olive 04HD, Sony DTC-59ES DAT, McIntosh 4300V, JBL 4312A

Last edited by jdandy; 07-05-2016 at 04:55 PM.
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  #9  
Old 07-05-2016, 07:13 PM
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Quote:
Originally Posted by jdandy View Post
After owning tube equipment since the late 1960's, up and through the tube gear I presently enjoy, I have learned a few things about tubes along the way. Vaccum tubes have piqued my curiosity for many years. How they work, how they are manufactured, and what makes one tube superior to another has provided countless hours of reading and research through the years. Some of the information has stuck in my brain and is easily recalled. Some other needs for information will cause me to go digging for answers. Either way, I find vacuum tubes to be interesting and enjoy listening to well designed tube amplifiers running high quality tubes.
+1. Absolutely. Plus there's lots to find on the web about them. I agree with jdandy here. Tubes provide endless fascination and fun.

Nothing like glow bottles at night.
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