It's probably one of the most misunderstood things about vacuum tubes:  The name on the tube is the company that made it right?   Well actually the answer is No - and that's why it can be so confusing.

The tube making giants of the 1940's, 50's and 60's were Amperex / Mullard / Philips / RCA / Sylvania and GE ( General Electric ) to name most but certainly not all.  While it's true that they made tubes with their company name on the glass - the bulk of their production was devoted to making tubes under contract for other companies.

Remember the Zenith TV your family had in the living room back in the 70's?  All the tubes inside were labelled Zenith and Only Replace with Genuine Zenith Tubes.   Brilliant marketing but somewhat deceiving since Zenith didn't make tubes. They bought them in bulk from GE and Sylvania and the supply contracts required that the tubes were labelled Zenith.  The public didn't know that - it made sense to replace a Zenith tube with a Zenith tube.  Zenith knew that other brands could be used instead but they were protecting their repeat business.

This is just one example - multiply it by the 100's of other companies making TV's, organs, radio receivers,  amplifiers, medical / test equipment and you can see how confusing this became. All those different names on the glass but still only a handful of companies making tubes.

So how do you know who made a tube?  Learn to read the production codes - not the brand names.  Each tube will have markings which show two things - the company that made it and when it was made.  Once you learn these codes it makes tube identification easy and allows you to find good deals.  There are a lot of good resources on the web that will teach you about production / date codes.

It's a small picture but I have a larger version in my auctions.   Four 12AX7 tubes made by Amperex: some labelled for Rogers, another for Electrohome and the 1st one as an Amperex Bugle Boy.  Guess what?  They all sound the same.  Why? Because they were made on the same assembly line, using the same materials and method of construction and with the same testing afterwards.  If Amperex made the tube it's going to sound like an Amperex tube.  Just like Johnnie Walker scotch tastes like Johnnie Walker scotch regardless if it was packaged in the familiar bottles or a glass mason jar.

The only difference is the tube on the far left will sell for double the price - because it has the Bugle Boy logo.  We've been brought up to think that the label on the outside is the most important factor and that simply isn't the case.   The label means nothing - who made the tube is what your ears hear.

I've sold a lot of these hidden gems:  the Mullard / Amperex / Philips 12AX7 that have someone else's name on the glass but still give you all the tone you expect from these companies.   Check out seller reegs67 for additional info and supportive feedback.

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