It is a mistake the way it is written in the Philips code list. But there are several "mysteries" there because, for example, the factory with code 5, which is on the majority of metal base pre-EL34 tubes is not present in that list. If you look here you see Toshiba Japan.
But the metal base tubes with 5-code were made in Eindhoven and sound like other tubes manufactured there. Then there is the "K" code missing from this book, but on mullard.org you find it as:
And if you look more you can find the K-code was related to Cossor, for example here.
So as I said, many misteries and the resources from which we can learn are slowly disappearing, people directly involved with these are less and less present to help. When I reply I do not make it to correct or draw attention, my main focus is to contribute and put info in several new forums so the available amount of information remains constant. These photos I make are from my personal collection, made mostly for tube identification, this is why are more "technical" showing several areas of the tube than beautiful. I keep the tubes stored and with these I try to remember how they look. I also made notes and stored offline interesting things I consider valuable and I try to repost them where needed, so they are again available.
In my view, if you are in general interesting in tubes you need to have a subscription to radiomuseum.org. There is a lot of nice information there and they need our support. Then for 6L6/EL34 there are 2 nice books written by Pasquale Russo, I recommend those. This is the EL34 guide and this is the 6L6 guide. The guides contain a lot of photos and go beyond the title, EL34 guide covers the pre-EL34 era, I think it starts on EL1 and so on and the 6L6 one covers also the british KT-tubes. (PS. a pair of EL1 was sold yesterday on Ebay by Dein Radio, I wonder who bought them, 15 EUR/pair). In the end, of course, there is a lot of free information and books on the Frank's Electron Tubes website.
Now coming back to E-code french tubes, I will show one more. This is a PE06/40N with codes DU8/E4E. As you can see it has on it "Made in France". Some people confused these tubes coding and identified them as D-code made in Hamburg, Germany. But "DU" is the tube type. And I know this because I have 2 tubes of the same type and saw the codes on the other.
This is the other:
So we have 2 pieces of PE06/40N (N=this 5 pin socket common to 807 tube, these work in the same adapters, P=european side contact version). One is DU8/E4E and other is KL/DUF. DU=tube type. 8 and F are revision codes and then we remain with the actual date code and manufacturing factory. K and E. So the brown base one is a French made tube in the same Hyperlec Brive location.
Since we are here, let's see a PE06/40P:
I have no clue how to decypher the "J20" code and I have the same problem with many EL50. Old code, I could not find information about it.
And let's end in style with another very interesting tube, the SFR P17C. People here know how much I love the red series and EL50, and this one, P17C is a tube some claim it sounds better. In fact it's just a variation of the PE06/40N, biases the same as with the ones above and not like EL50/4654 and you can see this when you measure these tubes.
They made in France some equivalents to some tubes which I have no clue why they named differently. The P17C is a variation of PE06/40N (which is also uncommon name for me) but they also made for example an 807 equivalent (5933) called P17W, this one:
These french tubes are very nice sounding, smooth and nice but usually loose on the separation and detail retrieval, so pairing is essential to make these sound good. Of course, musical genre is important and in my view this romantic french sound matches perfectly jazz or blues.
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