# Tube Identification?



## davetcan (Feb 27, 2006)

Can anyone identify these tubes please? I've had them laying around for awhile. They "look" like 12AX7's but I'm concerned they may not be. No markings on them at all except for the 100/90 and 100/105 in marker on the glass. One of the top plates also has "303" on it in what looks like pencil.


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## davetcan (Feb 27, 2006)

More pics. I've looked at a lot of close ups and haven't seen anything with the double top spacer configuration.


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## zdogma (Mar 21, 2006)

They look like Chinese 12AX7's to me, let me check a couple in my box to confirm.


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## zdogma (Mar 21, 2006)

Yep Chinese origin 12AX7's, I think 8th generation. They're the only tube i've seen with that plate configuration.


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## davetcan (Feb 27, 2006)

Thanks. As I've been looking around it seems these may be "triple mica spacer" tubes, still not sure if they'd be 12ax7's or at7's though. Or anything else for that matter  





zdogma said:


> They look like Chinese 12AX7's to me, let me check a couple in my box to confirm.


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## zdogma (Mar 21, 2006)

Here's a thread on harmony central about them, i don't think they make a 12AT7 or any other tube with that plate structure. There's a good pic of the innerds:

http://acapella.harmony-central.com...guang-tube-12AX7-12AX7A-12AX7B-what-different


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## davetcan (Feb 27, 2006)

Perfect, that sure looks like them. Thanks a lot.



zdogma said:


> Here's a thread on harmony central about them, i don't think they make a 12AT7 or any other tube with that plate structure. There's a good pic of the innerds:
> 
> http://acapella.harmony-central.com...guang-tube-12AX7-12AX7A-12AX7B-what-different


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## nonreverb (Sep 19, 2006)

Yup...they look like Chinese 12AX7's to be as well.


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