Yes, there are indeed 7 versions of REAL xf1 EL34 prodcued by Mullard as observed by our member William "vinylforever" : (beginning of original message) Subject: 7 versions of Mullard Large Bakelite Base From: vinylforever@my-deja.com Date: 2000/08/06 Newsgroups: deja.comm.hktubeaudio Hello Tim This is to answer your question on the different versions of Mullard large bakelite base EL34. I think I better start a new thread instead of following the TKN EL34 thread. I have made a count and there are actually 7 versions of the large bakelite base Mullard, rather than 6. I use the following four main features to differentiate them: (A) Base There are four types, each of which I've given a name: 1. Moustache base: oldest and rarest type of Mullard bakelite base; brown color, with a small hole between the eighth and the first pin. There are two elongated holes, like a moustache, on both sides of the third pin. No hole in middle guide pin. 2. Concave-no-hole base: second oldest type; brown in colour, with concave lines between pins. No hole in middle guide pin. 3. Concave-with-hole base: Similar to second oldest type, brown colour, with concave lines between pins, but with hole in middle guide pin. 4. Numbered convex base: last type of Mullard large bakelite base; color changed to blackish brown, convex lines between pins, numbers 1 to 8 next to each corresponding pin. Hole in middle guide pin. (B) Pin Two types: 1. Wired sixth pin: internally, sixth pin wired to lower mica layer. (For grounding purpose?) Metal base TKN EL34 or metal base Dutch-made EL34 both have sixth pin internally wired to lower mica layer. For Muallard large bakelite base, only earliest ones have sixth leg wired. 2. Unwired sixth leg: sixth leg not internally wired to lower mica layer. (C) Glass top Two types. I use guitar terminology and call them: 1. Flat top: glass top relatively flat (like Amperex EL34 tubes) with slight finishing wringles in the centre. 2. Arch top: glass top arched (more like TKN EL34 tubes), no finishing wringles. (D) Getter Three types: 1. Double overlapping getter rings 2. Single oversize getter ring: size of ring about twice of the double-getter ring type 3. Double parallel getter rings Based on these four features, I found 7 versions of large bakelite base Mullards: Version 1: Moustache base, Wired sixth pin, Flat top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B7B. Version 2: Concave-no-hole base, Wired sixth pin, Flat top, Single oversize getter ring. The earliest one I found for this version has the code Xf1 B7K. Version 3: Concave-no-hole base, Unwired sixth leg, Flat top, Single oversize getter ring. The earliest one I found for this version has, again, the code Xf1 B7K. Version 4: Concave-no-hole base, Unwired sixth leg, Flat top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B8F (though there are also Version 3 with B8F code). Version 5: Concave-with-hole base, Unwired sixth leg, Arch top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B8H. Version 6: Concave-with-hole base, Unwired sixth leg, Arch top, Double parallel getter rings. The earliest one I found for this version has the code Xf1 B8J (though I also found some Version 5 with B8J code). Version 7: Numbered convex base, Unwired sixth leg, Arch top, Double parallel getter rings. The earliest one I found for this version has the code Xf1 B0H2. This is the blackish brown base version which I think did not undergo any change until Mullard switch to the smaller base Xf2's. Isn't this fascinating? Which type sounds best? Honestly I don't know for sure. The rarest ones I have only one or two pieces, so I cannot really test each version as such. But the watershed in sound seems to be the flat top Vs the arch top. Overall, I have a slight personal bias towards the arch tops. Which is good news, of course, because they can be found more easily than the flat tops. The earlier flat tops seem to sound more like Dutch Amperex tubes -- though I may be influenced by its appearance to think so! (Or could they be made in Holland, like the metal base Mullard?) I have not acutally exhausted the minute construction differences of these tubes. If you look at the tubes, two of the support posts lead to the large cooling wings at the top. But for the remaining two support posts, they have small "ears" attached to them, both at the top and the bottom. There exist some differences in shape or materials for both the large cooling wings and the small "ears"... As I said, I might eventually do a little book or web page on this :-))) Regards William (end of original message) ------------------------------------------------------------------------------ You can view this message and the related discussion by following this link: |
7 Versions of Mullard Type 2 xf1 EL34? |
Yes, there are indeed 7 versions of REAL xf1 EL34 prodcued by Mullard as observed by our member William "vinylforever" : (beginning of original message) Subject: 7 versions of Mullard Large Bakelite Base From: vinylforever@my-deja.com Date: 2000/08/06 Newsgroups: deja.comm.hktubeaudio Hello Tim This is to answer your question on the different versions of Mullard large bakelite base EL34. I think I better start a new thread instead of following the TKN EL34 thread. I have made a count and there are actually 7 versions of the large bakelite base Mullard, rather than 6. I use the following four main features to differentiate them: (A) Base There are four types, each of which I've given a name: 1. Moustache base: oldest and rarest type of Mullard bakelite base; brown color, with a small hole between the eighth and the first pin. There are two elongated holes, like a moustache, on both sides of the third pin. No hole in middle guide pin. 2. Concave-no-hole base: second oldest type; brown in colour, with concave lines between pins. No hole in middle guide pin. 3. Concave-with-hole base: Similar to second oldest type, brown colour, with concave lines between pins, but with hole in middle guide pin. 4. Numbered convex base: last type of Mullard large bakelite base; color changed to blackish brown, convex lines between pins, numbers 1 to 8 next to each corresponding pin. Hole in middle guide pin. (B) Pin Two types: 1. Wired sixth pin: internally, sixth pin wired to lower mica layer. (For grounding purpose?) Metal base TKN EL34 or metal base Dutch-made EL34 both have sixth pin internally wired to lower mica layer. For Muallard large bakelite base, only earliest ones have sixth leg wired. 2. Unwired sixth leg: sixth leg not internally wired to lower mica layer. (C) Glass top Two types. I use guitar terminology and call them: 1. Flat top: glass top relatively flat (like Amperex EL34 tubes) with slight finishing wringles in the centre. 2. Arch top: glass top arched (more like TKN EL34 tubes), no finishing wringles. (D) Getter Three types: 1. Double overlapping getter rings 2. Single oversize getter ring: size of ring about twice of the double-getter ring type 3. Double parallel getter rings Based on these four features, I found 7 versions of large bakelite base Mullards: Version 1: Moustache base, Wired sixth pin, Flat top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B7B. Version 2: Concave-no-hole base, Wired sixth pin, Flat top, Single oversize getter ring. The earliest one I found for this version has the code Xf1 B7K. Version 3: Concave-no-hole base, Unwired sixth leg, Flat top, Single oversize getter ring. The earliest one I found for this version has, again, the code Xf1 B7K. Version 4: Concave-no-hole base, Unwired sixth leg, Flat top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B8F (though there are also Version 3 with B8F code). Version 5: Concave-with-hole base, Unwired sixth leg, Arch top, Double overlapping getter rings. The earliest one I found for this version has the code Xf1 B8H. Version 6: Concave-with-hole base, Unwired sixth leg, Arch top, Double parallel getter rings. The earliest one I found for this version has the code Xf1 B8J (though I also found some Version 5 with B8J code). Version 7: Numbered convex base, Unwired sixth leg, Arch top, Double parallel getter rings. The earliest one I found for this version has the code Xf1 B0H2. This is the blackish brown base version which I think did not undergo any change until Mullard switch to the smaller base Xf2's. Isn't this fascinating? Which type sounds best? Honestly I don't know for sure. The rarest ones I have only one or two pieces, so I cannot really test each version as such. But the watershed in sound seems to be the flat top Vs the arch top. Overall, I have a slight personal bias towards the arch tops. Which is good news, of course, because they can be found more easily than the flat tops. The earlier flat tops seem to sound more like Dutch Amperex tubes -- though I may be influenced by its appearance to think so! (Or could they be made in Holland, like the metal base Mullard?) I have not acutally exhausted the minute construction differences of these tubes. If you look at the tubes, two of the support posts lead to the large cooling wings at the top. But for the remaining two support posts, they have small "ears" attached to them, both at the top and the bottom. There exist some differences in shape or materials for both the large cooling wings and the small "ears"... As I said, I might eventually do a little book or web page on this :-))) Regards William (end of original message) ------------------------------------------------------------------------------ You can view this message and the related discussion by following this link: |
The picture above shows the three types of large bakelite bases. The one on the left of the picture is the oldest and rarest type: Brown in color, with a small hole between the eighth and the first pin. There are two elongated holes, like a moustache, on both sides of the third pin. No hole in the middle guide pin. I'll call this type the "Moustache base". The one in the middle is the second oldest: Brown in colour, with concave lines between pins. No hole in the middle guide pin. I'll call this type the "Concave-no-hole base". The third type (not shown in the picture): Similar to the second oldest type, brown in colour, with concave lines between pins, but with a hole in the middle guide pin. I'll call this type the "Concave-with-hole base". The fourth type (on the right side of the picture) is the last type of Mullard large bakelite base: Dark brown color, convex lines between pins, numbers 1 to 8 next to each corresponding pin. Hole in middle guide pin. I'll call this type the "Numbered convex base". |
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