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Tube newbie question on price differentials for "same" tubes


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Hi, I was looking at a pair of 12BH7 tubes and on this site  , it seems one pair is USD69 and the other pair is USD149. Both seem to be "sylvania tests NOS 12BH7A Gray Plate O Get matched pairs"  .  Here are the links, if any of the expert tube users could please explain the reason for the difference and if the more expensive one is worth it? 

 

https://www.vivatubes.com/tests-nos-matched-pair-sylvania-usa-12bh7a-grey-plate-o-get-tubes/

 

https://www.vivatubes.com/tests-nos-matched-pair-sylvania-us-12bh7a-grey-oval-plate-o-get-tubes/

Edited by sufioz
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Different plate structure, one is oval one is not.

 

As far as the oval being worth the extra, maybe wait for @xlr8or our resident tube fanatic.

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Oval anode plates were manufactured by GE. This is the reason for the higher cost. However, there are far superior sounding 12BH7's. The 1950’s AWV locally manufactured black plates with 90-degree square getters are legendary. Others that are worthy of consideration are very early 1950's CBS Hytron black plate 12BH7's with white print and 90-degree horseshoe or 45-degree rectangular getters. Brimar mid 1950's 12BH7's with black plates and 90-degree rectangular getters are also worth sourcing.

 

Edit: I would recommend acquiring singles to make up pairs.

Edited by xlr8or
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1 hour ago, xlr8or said:

Oval anode plates were manufactured by GE. This is the reason for the higher cost. However, there are far superior sounding 12BH7's. The 1950’s AWV locally manufactured black plates with 90-degree square getters are legendary. Others that are worthy of consideration are very early 1950's CBS Hytron black plate 12BH7's with white print and 90-degree horseshoe or 45-degree rectangular getters. Brimar mid 1950's 12BH7's with black plates and 90-degree rectangular getters are also worth sourcing.

 

Edit: I would recommend acquiring singles to make up pairs.

Thanks so much for the comprehensive guidance. Much appreciated.

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  • 2 weeks later...

Hi @xlr8or, if I could tap into your knowledge again.....is 5687 a good replacement for 12bh7? I am dabbling in tube rolling and they seem a lot cheaper than the 12bh7s in the NOS land. 

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12BH7's and 5687's are different tubes and not pin comptabile. Even with tube adapters they have different operating points.

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Thanks so much for clearing that up. 

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