April 1956 British-made metal base Philips EL34s?

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April 1956 British-made metal base Philips EL34s?

Postby Jeff West » Sun Jan 18, 2009 3:18 am

I had noticed awhile back that in the Vietnamese site that Dai posted in a thread below (re: GEC ECC81, 6/20/08), i.e.,


in the EL34 section they show "the difference between British and Dutch made metal collar EL34s", and indicate that the former is reflected in a second bottom groove effect on the collar that doesn't appear on the Holland made ones, i.e.,


I had discussed with a couple of hard core metal base followers but we weren't sure just what to think . . .

So this is quite interesting:




Another pair of metal bases with said groove, no stamped codes in steel but etched codes on glass "SY0 R6D". Would look to be bona fide for 1956 Mitcham manufacture.

Anyone else have or seen any of these?

Early 1957 Xf1s would still seem to be the first Blackburn EL34s (at this point!), but perhaps not the first British/Mullard Philips ones after all. These certainly otherwise resemble the Dutch ones in most respects. I think the getter shield has distinctions . . .

Mitcham was older than Blackburn within Mullard, served more as headquarters and also always had lots of R&D going on there I think, so maybe this makes sense in that context (?). Maybe they finished some there (pumping and sealing) using exported components from Eindhoven? At this point I'm still assuming that the "5" stamping on metal base EL34s before the date codes indicates Eindhoven, even though "5" seems to be MIA on all the old lists!

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Re: April 1956 British-made metal base Philips EL34s?

Postby Jeff West » Sat Oct 17, 2009 12:20 pm

How is everyone? Happened to see another one of these, Mullard Mitcham-made Metal base, codes are again on the glass and one month later than the previous pair ("SY0 R6E" 5/56). Second groove on the base still seems to be a consistent way to notice these.


Jeff West
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Re: April 1956 British-made metal base Philips EL34s?

Postby David B » Sun Dec 06, 2009 12:23 pm

Hi Jeff,

How do those metal base xf1's either British or Dutch sound in a Marshall ? I had heard early brown base xf1's in a 50 watter but that was may years ago.
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