Dawn of EL34s

NOS, modern, dating and identifying.

Dawn of EL34s

Postby Jeff West » Sun Jun 15, 2008 1:40 pm

It's been clear that a version the EL34 was developed, tested and named by Philips by mid 1949, because they were publishing detailed materials well before the end of that year that listed it and plotted performance characteristics.

Friend Peter Field in Australia recently sent a photo of a very early one of the original style, adapted from Philips' earlier loctal-like EL60, with codes ("5W" over "KEO" on the base) that can indicate they were stamped in 5/49. Pretty sure that's the earliest dated EL34 specimen I've heard of. Seemed fitting to post here.

I suspect they didn't foresee in Eindhoven then all of the settings their new pentode design would find itself in during the coming years!

Jeff

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Last edited by Jeff West on Wed Jun 18, 2008 7:47 pm, edited 1 time in total.
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Postby 908ssp » Sun Jun 15, 2008 11:17 pm

I was wondering the other day if the EL34 might be a cheaper tube to build because the side of the glass are straight compared to say an KT66? Seems silly maybe but anything that adds to the steps in manufacturing adds cost. And a cheaper tube can make your profit margin that much better.
Alex

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EL luv

Postby swankmotee » Mon Jun 16, 2008 4:02 am

I am a stone cold lover of pre-80's RFT 34's and have loaded them into all my vintage NM 100wt heads and to me they are the definitive sound of classic hard rock! I definitely love my Mullards too but they just don't grind as hard or scream the same way as the east German glass does. I've been lucky to have found some NOS sets that posess this classic sound and my amps continue to turn ears around here in Nashvegas. Hopefully someday one of the companies will produce something that will be able to compete with the old glass but I'm not waiting around to find out!
www.myspace.com/tommyhatcher for the sound of THUNDRIN' Marshall 100 watters!
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Postby David B » Mon Jun 16, 2008 5:31 pm

Hi Jeff,

Cool stuff,look forward to seeing the pictures. Always wondered if the names of the people who developed this valve are known ?

I keep hearing about pre 80 RFT 34's, are they much different than the eighties version?

David
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Postby swankmotee » Mon Jun 16, 2008 7:35 pm

David B wrote:Hi Jeff,

Cool stuff,look forward to seeing the pictures. Always wondered if the names of the people who developed this valve are known ?

I keep hearing about pre 80 RFT 34's, are they much different than the eighties version?

David


BIG TIME! I spent quite a few years trying to dechipher what the differences were and Tubegetter and some others on the plexiPalace site did some serious decoding of the numerical system that RFT used to label their tubes through the years which opened my eyes to the best production periods for these. One of the big problems when trying to date these is that they are identical looking internally but without markings that accurately denote dates of manufacture which is really confusing. Alot of these tubes were rebranded with other makers marks (Siemens) and had NO markings whatsoever for dating or origins! What they found was that during the breakdown of the cold war years the RFT plant basically let alot of the production guidlines slide and the tubes suffered which myself and alot of other users noticed because the 80's versions sounded really bad compared to their earlier counterparts, they also had a much higher failure rate which was unheard of with the earlier models. I went on a long quest to gather up some older models and can truly say they are without a doubt the best 34's for my tone and still farily affordable so get some while you can and see what you think!
www.myspace.com/tommyhatcher for the sound of THUNDRIN' Marshall 100 watters!
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Postby David B » Mon Jun 16, 2008 7:55 pm

This warrants some investigation,Oh I can feel my wallet getting lighter :twisted:
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Postby dai h. » Tue Jun 24, 2008 9:33 am

saw these (which are Matsushita Densi Kougyou, or Matsushita Electronic Industries) Technical Notes for 6CA7 and 6BQ5:

http://www.ne.jp/asahi/myamada/tube/shicopy/6ca7.gif

http://www.ne.jp/asahi/myamada/tube/shicopy/6ca7_2.gif

and these are dated 1957 (according to the author of the site), so less than ten years from 1949. (Apparently business connections existed between Matsushita and Philips pre-war, so I guess there was already some basis for the similar tubes, transistors, etc. in the post war period.) For example the top picture in the next link (apparently a "National"--Matsushita's domestic brand 'til recently changed to "Panasonic" OC44 which looks very much like black glass encased Mullard germanium transistors. This is a chart where the author estimates the name changes based on references given at the bottom from sources dating from around late 50s.).

http://www.radioshounen.com/lolipop_dio ... r_suyi.htm

Also, one thing I wondered about EL34s is that there is a USSR to Western tube equivalents chart (at that big German site with numerous tube pics) and on it IIRC there was an equivalent for EL34 so I wondered if they actually made one, or maybe they just sourced from the Eastern block states like E.Germany and Yugoslavia (who did) and used a different name (their own nomenclature).
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Postby Jeff West » Tue Jun 24, 2008 1:20 pm

Hi Dai- Matsushita made and sold metal collar EL34s with National brand in mid/late 1950s, Tubegetter bought a couple of those and had photos on Metro site w/date codes I believe are 1956 IIRC, occasionally you see others of those on e-bay. I noticed you have an early black base one with "double Ds" dated 5/60, then w/in a few months after that they had a version with double overlapping halos. Incidentally, none of these have the Matsushita "hallmarks" of top seams or raised ridge on the plates. A funny thing about the overlapping halos version too is that it seems to have disappeared by early '60s, the ridges appear, they go to single halo etc. like the 1/66 version you show, Dai, but I have one (overlapping halos) branded Matsushita with their date codes indicating 1967, with the ridges and cross seams, so I guess you can find both in mid '60s.

One thing I remember about the National logo whether in Japanese or English is that they added the big black "N" behind it (on the boxes or literature) only at the very end of the '50s, '50s generally had a black circle.

On the tubes themselves, the screened triangle or delta-looking symbol (instead of the circular script National/Matsushita logo) on Matsushita branded specimens is a sure sign of latter '60s or later labelling. However, the time when they first went to using this seems to vary quite a bit across tubes, '66-'68?

The formal Philips technical agreement with Matsushita that really affected tube manufacture started 1952, so makes sense it impacted quickly in the initial EL34 era.
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Postby dai h. » Wed Jun 25, 2008 11:01 am

thanks Jeff I figured the flat top one was earlier but I had no idea of exact dates.

Jeff West wrote:I noticed you have an early black base one with "double Ds" dated 5/60, then w/in a few months after that they had a version with double overlapping halos. Incidentally, none of these have the Matsushita "hallmarks" of top seams or raised ridge on the plates.


this one (from the earlier link above) doesn't have the top seams but does show the ridges, or "ribs" (as some seem to refer to them):

http://www.ne.jp/asahi/myamada/tube/TUB ... 6CA7_M.JPG

this is the picture next to it (original page follows: )

http://www.ne.jp/asahi/myamada/tube/TUB ... A7_M_P.JPG

http://www.ne.jp/asahi/myamada/tube/TUBE_LIB/power1.htm

and double getters are showing (but not sure if the intact tube and the disassembled one are the same)


On the tubes themselves, the screened triangle or delta-looking symbol (instead of the circular script National/Matsushita logo) on Matsushita branded specimens is a sure sign of latter '60s or later labelling. However, the time when they first went to using this seems to vary quite a bit across tubes, '66-'68?


on this site (which I think you've seen previously), the author says the marking changed to the triangular logo in a four year period from '65 on, so that sounds like you got it right.

http://radiomann.hp.infoseek.co.jp/Home ... ntode.html

re: the logo, apparently this one (M with arrow) was the original company logo (from 1920) :

http://panasonic.co.jp/company/history/ ... mg/025.jpg

however in 1943 (of course during the war), due to increasing chauvinism use of Western Romaji ("Roman letters") "M" came to be considered politically incorrect (other things like changing terms for "baseball" as well as baseball terms such as sutoraiku ("strike"), etc. were changed) and therefore was changed to the "mimatsuba" (triple pine needle?--something like that) triangular logo:

http://panasonic.co.jp/company/history/ ... mg/076.jpg

(actually reading the story behind the logo and looking it now makes it appear a bit more militant, with its sharp pointy edges, sort of looks like a ninja throwing star or something, lol...)

The formal Philips technical agreement with Matsushita that really affected tube manufacture started 1952, so makes sense it impacted quickly in the initial EL34 era.


the San Francisco Peace Treaty (formally ending WWII) was '51-52 so that seems pretty quick.
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Postby Jeff West » Thu Jun 26, 2008 12:14 pm

This is interesting (and all the pages) regarding things that went on immediately postwar and through the '50s, if you haven't seen:

http://panasonic.net/history/founder/chapter3/story3-04.html

I have a few more comments to add shortly!

Jeff
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Postby dai h. » Thu Jun 26, 2008 1:10 pm

thanks for the link Jeff. I did read someone making a comment about Matsushita providing managerial expertise and (reading that page) apparently it is true.

Have you ever seen this book? Don't have this, but I saw (stumbled into whilst googling) an excerpt at buy.com, and there was some interesting info on US-Japan tube connections:

http://www.buy.com/prod/we-were-burning ... 80231.html

I remember from a history course that Japanese companies apparently made lots of money from American procurements during both the Korean and Vietnam Wars. There is a bit about that in the excerpt and was sort of realizing that (considering the timeframe--that is, early '50s) the Korean War must have been pretty much an "all-tube" war. Wonder what sort of effect on tube technology, production, etc. in Japan that had.
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Postby Jeff West » Fri Jun 27, 2008 2:43 pm

Hey- No, I haven't seen that book, although maybe I'll try to get one, looks interesting.

I do have "History of Electron Tubes" by Sogo Okamura(ed) 1994, given by my wife last Christmas (ok, so I provided a few possible ideas earlier, on request). It has some things that seem pertinent to different aspects of the discussion. I think portions of it are online. Page 79 has a figure with "trademarks" (logos; 60 of 'em) of Japanese vacuum tube manufacturers at the end of 1948. It's actually attributed to another source, N. Matsumoto. Present are several that are familiar from later, inc the Hitachi eye, the Matsushita "National" in circle, NEC in diamond, TEN slanted in broken circle. The "three pine needles" one doesn't really appear, although there's another one that kind of resembles a ninja throwing thing. I had wondered whether the poetic "three pine needles" was an accurate translation from the Japanese of the name of that symbol, or a wild babelfish artifact!?


This book also discusses economic and world factors. There's an interesting chart (p.62) and discussion that purports to compare Industrial growth 1900-1969 in Japan, vs. USA, vs. UK, Germany, France, Italy (shows full recovery by about mid 1954 in Japan to highest pre-War/War level, then continued exponential rise, BTW). Regarding "receiving tube production" in particular, he also charts (p.64) purported USA vs Japan production in billion pieces by years from 1922 (US)/1935(Japan) to 1980. US leads until late '60s but achieves approx asymptote after about 1950 while Japan continues to rise, with total production purported to almost come together in about 1969. Then they both show precipitous dropoff thru the '70s. I'll try to get some stuff scanned and posted here.

The Okamura book is not especially plentiful with juicy details about specific Japanese manufacturers, details of when EL34s got ribs, etc. but does include some interesting manufacturing procsses and evolution.

I'll come back to EL34s esp Matsushitas next and maybe in later post. For now, the dating codes for Matsushita/National branded tube specimens (not just 6CA7s) from about 1959 until '70s is simple two character code I think with last digit of year and simple month code A-L (none skipped). Usually, this pair is repeated, i.e., printed two or more times on the tube. Often on the base in '59-60 for EL34s but on the glass after. Before about '59, maybe a little earlier, they usually seemed to use a two letter code where the second one was as above, for month, and the first was a letter designating year. Kind of like British mil and GEC, except that the letters started in Z in 1946 not A and ran backwards! And none skipped. Note that these codes unlike say Philips etch codes are not manufacturing date but rather printing/presumably shipping, and seem mostly if not only to be on ones actually branded as Matsushita/National. Thus presumably the dates may be significantly later than manufacture on occasion, which might explain some apparent anomolies in evolution of details, going by these dates.

Manufacturing vs. labelling and shipping dates might be worthy of a thread too. Maybe we can set down the RCA actual manufacturing dates often encoded into the octagons and etched tube numbers (along with the factory of manufacture) on RCA-made specimens, I don't know any single source for the former, although the factories part is largely known from saved RCA technical pubs.

I'm long familiar with the radiomann site, thanks purely to you Dai. The thing about the "pine needles" hawkish triangle symbol based on what I've seen might be interpreted as "they started applying it on occasion only in 1965". It may be much older, but at least from what I've seen, on the audio tubes we crave, it's a latish '60s and '70s marker. So a matsushita branded tube with say "1A" and the triangle will certainly be 1/71 not 1/61; the latter would have the circle logo.

The Okamura book, consistent with other sources, does specifically confirm that all Matsushita receiving tube manufacture ended in 1979.

JAW
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Postby dai h. » Fri Jun 27, 2008 8:14 pm

I had wondered whether the poetic "three pine needles" was an accurate translation from the Japanese of the name of that symbol, or a wild babelfish artifact!?


lol sorry Jeff you can blame "three pine needles" solely on Daifish. :wink:
I'll try to explain. In Mimatsuba, there are three Chinese characters. Mi = three, matsu = pine, and ba = leaf. So the last one is leaf but seemingly pine "leaves" are "needles" (since they are shaped that way), so I wasn't really sure which was more appropriate. I saw the mimatsuba symbol on a site listing some kamon (family seals/symbols akin to "family crests" I think), so the symbol may not have been a Matsushita invention. Maybe they saw it more fitting from a nativist sort of perspective and more in tune with the political climate.

Also, thanks for the explanation on the Matsushita dating code. It did seem to be some sort of two symbol thing, but I never bothered trying to work it out.

And, sorry if I went a little too tangential. I'll try to be more organized and on topic. :oops:
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Postby Jeff West » Tue Jul 01, 2008 9:51 am

My conscience would never let me be critical of tangentiality, given my own predilections on amps boards.

I got out a few Matsushita branded EL34s with date codes 1960-68, maybe along with yours Dai and the ones pictured on that site we can formulate a timeline for changes, seems like the characteristic features changed one at a time. I think after the end of the '60s they stayed about the same. I've noticed that most of those RCA branded ones that say made in England have RCA dates of about 1971-73, could have been made significantly earlier but I don't think too much earlier in that case.

J
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Postby dai h. » Tue Jul 01, 2008 6:17 pm

put a couple more pics of the flat top M.EL34 if that helps any. Also, do you know anything about different types? Specifically, I understand there were different markings (letter in a circle). For example the flat top has S in a circle. IIRC that meant "industrial use".
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