Phillips was a Dutch conglomerate that owned many of the popular European tube manufacturers, Amperex, Mullard Siemens, Valvo, etc. Tubes from one manufacturer often would be labelled with the name of another manufacturer. To find out where and when the tube was actually made you have to look at the etched tube codes. Here is a listing of all those tube codes:
D:MyFilesWordPerfectPhiltitle.PDF (pocnet.net)Etched tube codes can be hard or too faint to read, but if you want to know what you’re getting, you need to check these codes. There are probably people out there who can etch counterfeit tubes, but if you stay with reputable sellers, you should be OK.
If you decide to use the PHILIPS FACTORY VALVE CODES linked above, you only need to be concerned with the ’NEW CODE’ not the ’OLD CODE’ as illustrated on page 3.
NOS tubes are kind of a side line of high-end audio. I personally enjoyed learning about them and rolling them. If it doesn’t sound like fun to you, just go with new production tubes. That’s much cheaper and easier. Or, if you want to try NOS tubes, I recommend buying them from a reputable dealer and taking his advice. Learning about them and buying off ebay is very time consuming and higher risk.
There are reputable sellers on ebay with great tubes, but there are also crooks. No surprise there. You can find good European sellers on ebay, for example.
There are also tube manufacturers not owned by Phillips, like Telefunken, who use different methods of identifying their tubes. So it can get complicated.
