Help identifying Preamp tubes

B

bwgintegra

Well-known member
Please see pictures and give any inforamtion you can on these preamp tubes. I've had most of these for 10-15 years and don't know much about NOS preamp tubes. I have done some google research but I know some members have good knowledge about these tubes.

Top two right tubes are 12AU7's and bottom two right are 5751's

Top row 2nd tube is a modern tube with no markings





 
are you selling them? I see one or 2 RFT's in the bottom row I'll take off your hands if they are good :)
 
okay i had to open a couple windows to look.
Bottom row from lft to right first 4 in a row the 2 Phillips the Silvertone and one next to it are likely Blackburn Mullards and / or Amperex Holland.
Still going to the right on bottom from what i just said above is an RFT. The one directly above the RFT on the 1st row is another RFT.
The 5751 to the right of the RFT top is an Amperex 5751 made in Holland.
Back down to second row the 1st RFT i mentioned to the right of that [2 tubes are both american. first looks like a Sylvania, second may be RCA.
Top row second from left is a Chinese Shuguang.
Hard to tell the others.
 
Those D getter tubes look just like a few of my 1950s RCAs. The Amperex look like Mullards, with the etching I can barely see. The one Chinese like Dan said, and the RFTs as mentioned. Not sure of the rest. One has a strange circular getter I've never seen before. Covers the whole top of the tube, and has small dimples all the way around.
 
I agree with RacerXrated and Dan, completely.

I also think the far right, on the bottom row, is a short black plate RCA.
 
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RFT are the easiest to spot, they have the smallest getter and star-like micas.

US tubes probably have made in USA somewhere written on it.

European tubes have codes. Tubes from the 60ies to 70ies can have I61 - I65 etched on the lower half of the tube that indicates the tube type. This code is followed by a second code indicating production year and place. For example, if the second code starts with Bxxx it was manufactured in Blackburn = Mullard. If the code starts with a triangle, it was produced in Harleen Netherlands = Bugle Boy???

A 2A1 code indicates for an EI Yugoslavia.

Have a look on those two Philips tubes, they should have some sort of code.
 
Might be real Amperex.. Look for the Delta symbol.. Δ
Possible some relabeled EI smooth long plates.. Nice!
I see a couple Sylvanias I think..
 
Thanks for the information much appreciated

Here's another RCA I found tonight. Still need to figure out the 1st and 3rd tube


 
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