What'ya know about these tubes?

dromunds

Sorry about the poor photo, but can anyone tell me how anything about these tubes I found in my father's effects? The top left are Holland Amperex Bugle Boy 12AU7's with large halo getter from 1951 apparently, labeled 9-51. The top right are 12AT7 Telefunken angled small halo getters. The bottom row are Telefunken 12AX7's small halo's. Don't know how to determine age of the TFK's. I also don't have a tester so not sure how strong. There were also a few RCA 6AQ5A labeled 59-43 and 60-26, TFK EZ81, and RCA 6X4 labeled 60-22. Any comments appreciated. Thanks.

Msabot1

Do the TFK's have a diamond mark in the base glass between the pins?

pitdogg2

Amperex BB's were highly prized at onetime. Can't see these being any different unless they're used up. Most of the TFK are held in high regard

heiney9

dromunds wrote: »

Sorry about the poor photo, but can anyone tell me how anything about these tubes I found in my father's effects? The top left are Holland Amperex Bugle Boy 12AU7's with large halo getter from 1951 apparently, labeled 9-51. The top right are 12AT7 Telefunken angled small halo getters. The bottom row are Telefunken 12AX7's small halo's. Don't know how to determine age of the TFK's. I also don't have a tester so not sure how strong. There were also a few RCA 6AQ5A labeled 59-43 and 60-26, TFK EZ81, and RCA 6X4 labeled 60-22. Any comments appreciated. Thanks.

The Amperex are from 1959, not 1951. There should be a code etched towards the bottom of the glass something like this Gf0 on the first line and delta symbol 9B1on a 2nd line. Gf means it's a 12AU7 (ECC82) (short plate) (long plates are K6x) and "0" means it's the first build. Delta symbol mean Heerlen Holland. "9" is the last digit of the year, here we know it's 1959 not 1969 because it's the 1st build. If it was Gf6 delta 9C2, it's 1969 because it's a 6th and later build.

These are the first year of the short plates since it has the Large halo, later versions have a small Halo. Overall a very nice tube, best of the short plate Holland tubes. A little more rare than the small Halo.

The Tele's should all have a diamond embossed between the PINS. It's hard to tell from the photo, but Tele's usually have a thicker halo getter. The 12AX7 (ECC83) Tele was made both in smooth and ladder plates. Another nice tube, lots of them around.

The Tele's usually have a series of numbers starting with either B or U. B= Berlin. U= Ulm factories. The 4th digit after the letter is the last number of the year. Ie; if it's a 9 it could be 1959 or 1969 or even 1979. Earlier tubes mostly the 50's have a different code. Looks like this: ea or lr or ts. You need this chart to figure the year.

http://www.audiotubes.com/teledate.htm

The above link is a good tutorial, but I have found evidence that the tube codes changed earlier than the late 60's as stated. Tele's are an odd duck when it comes to exact dating. It shouldn't matter though because right through the late 60's into the early 70's they were extremely consistent.

Tele's are bit too lean for me, in my experience, but they are a great tube. Try for yourself before you decide.

Hope this helps

H9

heiney9

EZ81 and 6x4 are rectifiers.

The 3rd Tele from the left has a date code of "rb" = Jan. 1959

dromunds

Thanks for the help, I appreciate it. Maybe my Dad yanked these from tube gear around 1959 or 1960, as they appear to be all from the same time period and these tubes were stored together in a small bin. I've used some 1958-59 Holland Amperex Bugle Boy 6DJ8 D-getters in my phono stage that are very nice tubes indeed. HP labeled IIRC. No experience with 12AU7 BB's, but I'll have to see if I can get them tested and give them a shot in my amps. I have no TFK's other than 5695, will be interesting to see how the 12AT7 and 12AX7 TFK's sound. I hope they all test good! I'll have to find someone nearby with a tester now. Lol.

heiney9

I think you mean 5965. The 5965 and 12AT7 are equivalents. I used to run 5965's in my Dared in place of 12AT7's. I preferred the TFK 5965 over the TFK 12at7, but see what the 12at7's sound like.

The large halo ECC82's are very nice tubes, typical Holland sound and a bit more desirable than the later small halo tubes. Large halo tubes were made from late 1959 thru very early 1961. Most are dated from 1959 or 1960 and occasionally you'll see a 1961 date. They may also have 1st line code of Gf1, I think the Valvo short plates had the Gf0, can't remember off the top of my head.

JuanR

Where are you at? I live in Chicago and can test for you in my B&K 747B Tester...

Juan

dromunds

Yes, I meant 5965. Got a couple pairs on your recommendation! Lol. One pair through HochPt, that are now going back to him as part of the deal with Smglbrth for the Monitor 7's and the modded SDA 2A's that Paul got.

dromunds

Thanks JuanR, but I'm in Central Wisconsin. I'll check around here initially.