12AX7 Identification

[ethanbriz]

Hi guys. I hate to bother you with a question that I'm sure you experts get all the time.... but I really need help identifying a couple 12AX7 I came across. Im curious to know who made these thing, so any help would be appreciated!!!

They are larger than a typical 12AX7. I took a picture of one next to a Sylvania for reference. They are branded by United Electron, and say made in England. The bottom of the glass (center of the pins) reads "15" on one and "3" on the other. The short grey plates are off centered. The halo support rod is connected to the bottom spacer. Hopefully the pictures help clarify what I am talking about....

 

[Ty_Bower]

The wing shaped plates say "12AT7" to me. Other than that, I can't comment.

 

[ethanbriz]

They definitely say 12AX7. I suppose its not impossible that they were marked incorrectly, but it doesn't seem likely. Thanks for the input!

Anyone have any idea who made these things?

 

[Soonerorlater]

Can we take it that there are no seams on top?

Brgds Bill

 

[SY]

Eastern Europe, late '70s, early '80s. The innards look like 12AT7, but they're not. I have the same tubes branded variously as England, Holland, and Germany. For a while, I was getting them at Radio Shack. They are actually pretty good.

 

[dovla]

Rft

Looks like an RFT.
See http://cgi.ebay.com/ws/eBayISAPI.dll?VISuperSize&item=390184890944
or search ebay for RFT ECC83 to see a lot more pictures (and what they sell for)

 

[Sendy]

Tube on left side is GDR product - RFT, Funkwerk Erfurt etc. See pictures

RFT Anna Seghers Neuhaus ECC83 12AX7 Halo Getter - East Germany

pictures 138... 148

 

[kevinkr]

Eastern Europe, late '70s, early '80s. The innards look like 12AT7, but they're not. I have the same tubes branded variously as England, Holland, and Germany. For a while, I was getting them at Radio Shack. They are actually pretty good.

I had a bunch of these. I suspect they might be RFT or possibly an obscure West German maker/rebrander.. Sonotone?? IIRC (I had an Ampex deck that came with them stock.)

As SY says they actually sounded pretty good. I would say about as good as Mullard in fact if memory serves. They were very quiet which is important in a tape deck.