Identify Amperex Tube?

[Zap]

From my research I've discovered that Amperex tubes have a lot of variation between them - some made in Holland, some in Germany (Telefunken), and some made in Great Britain (Mullard).

I wanted to confirm the ID of this tube I found in my collection to know how I can acquire a few more of this particular variety. I think I've learned exactly how brand isn't the only factor that can affect sound, and I like the sound of this particular tube.

It's a white print, "Bugle Boy", D getter with a strip of metal attached to it, the plates look unique, only having holes on the one side as you will see in the pictures. Any impressions of this tube are appreciated, as well as a positive ID. I believe it is from Holland but the lettering is worn off on a good part of it. 49D is written below the ECC81/12AT7.

Thanks!

[jerluwoo]

These pages may help you out. Also I believe the telltale mark for Amperex Holland will be located on the base between the pins.


http://www.duncanamps.com/technical/tubenumber.html

http://www.akh.se/tubes/typsystem.htm

[Tom Bavis]

The "4" is a right triangle, I usually refer to it as a "delta", though it's not exactly that shape. That's the symbol for the Heerlen, Netherlands plant, so yes, it is Philips Holland. The "9" is 1959 - '69 codes had four characters.

[KaDe]

Philips codes