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Are DuMont Tubes any good?

Eafnb said:
I'm working on a project that needs a pair of 6DJ8 tubes and I am looking for a good pair for cheap. Whilst looking on eBay, I found some listings for a good price. I hear a lot about Mullard, RCA, General Electric, Sylvania, etc. But is Dumont any g
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Dumont are made by Sylvania they make a great 6v6gt, 6v6gta tube. I buy most Sylvania, tubes they all sounds great thoughout the spectrium.
 
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Many others here myself included know how to read codes I was just helping others by letting them know that Sylvania was not the only one who manufactured for DuMont as you stated
 
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Tube production was mostly automated from the 1920's on. Light bulb manufacturers had a head start - Tung-Sol, GE, Sylvania, Westinghouse (GE made the early RCA tubes). Each manufacturer had a limited number of production lines, each making one tube type at a time. Setup was complicated and shut down the line for a while, so tubes were made in large batches to reduce cost. So if a manufacturer was running low between batches for a particular number, it would rebrand other manufacturer's tubes. As the number of tube types increased, some tube numbers were only made by one or a few manufacturers and every other one relabeled those. Pretty much all of them made high volume tube numbers, but even those were relabeled when necessary.

And of course, Zenith, Emerson, Crosley, DuMont, etc. did not make tubes, they put their name on whoever's tubes they were buying that month. Every tube maker had dozens of stencils to label any tube with any name for quantity buyers.
 
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Here's what I got. I don't have a picture of the top and the bottom yet...

Based on this, I am positive these are Matsushita-made.
 

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Could be, they have the Euro design but I don't see the etch codes that would confirm a Euro plant actually producing them.

I'm looking at a GE and a Sylvania EL34 currently, both are Mullard produced, and they look very much like yours internally.
 
thats what I was poorly attempting to confirm. Looks like the Euro stuff, but no etch marks. Matsushita tubes look like Mullards but frequently don't have the etchings.
 
Just received a big box full of tubes from an amp buy and there were a few Dumont tubes in the box. ]

The box says Astrex Inc. 150 Fifth Ave Ny.

These are 6V6GT's

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Ken Boyd said:
Just received a big box full of tubes from an amp buy and there were a few Dumont tubes in the box. ]

The box says Astrex Inc. 150 Fifth Ave Ny.

These are 6V6GT's
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Astrex was the buyer/importer/rebrander for all kinds of electronics way back. Earliest legit mention I can find of them is in 1960/61 in newspapers (SEC filings and that kind of thing), latest is in the early-90s or so. They also bought factories for various electronics throughout the US. Their name appears on the boxes the Matsushita-made DuMonts came in. My take is they were one of those companies that bought OEMs in the US and figured out ways to juice them through cost-cutting, particularly by the 70s/80s. They eventually went bankrupt. I also found the name Dutrex connected to both around 1960 and it is listed as a tube importer/supplier for DuMont, then its name was changed to Astrex.
 
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