[david45]

Can anybody help? 

[avahifi]

Third phono down from the top shows the tube ID clearly, 12AU7.

This is an older tube as RCA has not made vacuum tubes for many years now.

The photos won't tell you if this sample is a good tube or not.

Frank

[kmmd]

You may want to check Brent Jessee's website for help: http://www.audiotubes.com/12au7.htm

With orange lettering, it may be these:

12AU7WA/6189 RCA Military/Commercial Grade

NOS, White Box. Blackplate, gold, orange or white lettering, extra support rods. A lower cost alternative to the 5814A.

$21.00

in Stock

I don't see the getter, but I hope this helps.

Ken

[FullRangeMan]

By the little I know on tubes I have never seen a such tall plate in 12AU7,
imo looks as a cheap JJ ECC802S plate, the JJ and EH ecc802 have both short plates.
https://www.tubedepot.com/products/jj-ecc802s-hi-performance-12au7-gold-pin-preamp-vacuum-tube

The posted photos above show a fantastique new tube paint labels,
very new, just like factory released, there are various labels and all
are new, the paint looks brand new, not a 50 years old paint.

To my eyes the top glass shape, getter and the top tip looks as a JJ ECC802S
tall plate current production not a expensive NOS RCA.

[FullRangeMan]

This big image can show better:

[david45]

Thank you very much for helping out! You guys are the best! 

[luisb]

Hi
They look like 12AU7 RCA clear top i have

[toober]

I am pretty sure that is an early to mid 60's true RCA 12au7.  Up until the late 50's RCA 12 series tubes had long black plates.  The long grey plates were in production for the shortest span, which transitioned into short grey plates around the mid 60's.

The clear top 12au7's I have, have the getter and flashing on the side.  As USA tube production started dying out, RCA sourced tubes from many European sources and re-branded them.   

[bfstrysik]

Does it have a 3 digit manufacturers code on it? RCA's manufacturing code was 274. If it was made by someone else, most of the time you will find their 3 digit code. And it looks like there is a date on it 60-17? Hard to make out from the pictures. 17th week of 1960. Looks like an original RCA 12AU7A clear top,  side getter, but I cannot make out the getter from the pictures. I have several of those NOS in my tube stash and the screen printing is in like new condition.

[toober]

This definitely isn't what people call a "clear top", I can see the getter stem extending from the top of the tube and the barium flashing is on the top. 
I have wondered if the "clear top" 12au7's sold in the U.S. weren't produced in Canada.  I recall having seen a Marconi (RCA's division in Canada) clear top 12ax7. 

As for the 274 RCA Code, they usually include it on their power tubes, but I don't believe I have ever seen it on their preamp tubes.
Does anybody have one that includes the 274 code?

[bfstrysik]

This definitely isn't what people call a "clear top", I can see the getter stem extending from the top of the tube and the barium flashing is on the top. 
I have wondered if the "clear top" 12au7's sold in the U.S. weren't produced in Canada.  I recall having seen a Marconi (RCA's division in Canada) clear top 12ax7. 

As for the 274 RCA Code, they usually include it on their power tubes, but I don't believe I have ever seen it on their preamp tubes.
Does anybody have one that includes the 274 code?

After a closer look at the pics with a magnifying glass, I believe you are correct. Missed what appears to be the getter stem upon my first observation.

[SET Man]

Hey!

   OK, let me jump in on this. I'm not an expert but here's what I know. The tube shown in the OP is 12AU7A, a variation 12AU7... I think it can be use in either parallel or series filament heater. And from the look of the "RCA" logo likely made in the late '60s through the '70s. As for who made it? I'm not sure, I can't see any factory code, but this likely was made by RCA.

  As for RCA "Clear Top" This is not a clear top for sure. Here's a quick snap of my RCA "Clear Top" on the right and typical 12xx7 tube on the left...



  You can still see the old "RCA" logo on the tube. As it name implies, the top of the tube is clear, the getter and flashing are on the side of the tube instead of the top.... O... K.

  By the way, a very good sounding tube. If you want a bit more open and livelier sound.

Buddy