Tube myths Joint Army Navy vs Non Joint Army Navy


Joint Army Navy tubes, commonly referred to as JAN tubes, were tubes produced for the military. Tubes meant for the military, had to meet certain specs, as outlined, in the contracts, each manufacturer, had with the military. Though some contracts, called for a specially produced tube(RCA 5692, for instance), the vast majority of them, called for the same specs, as the industries, who tubes were mainly produced for, had. Consumer use, of tubes for audio, was small in comparison. The reason most think JAN tubes, are "better" tubes, is based on the myth, that they are different tubes. If the specs on a tube, say 6922 for example, were the same, for the Navy, as they were for , say, Hewlett Packard, then both tubes, were ran off the same lines(at different times, as orders dictated), with the same tooling, and same personnel. They are essentially, the same tubes. Most factories, ran a certain number of tubes, and then labelled them, as the orders, dictated. So a tube labelled H/P, was the same as a tube labelled Beckman. So you tell me, "which tube is better?"
fletchj

Showing 1 response by nameci

I had some experience with 6dj8 family tubes: Amperex(Holland made), Siemens(German made), Philips(US made), and Sylvania(US made).
From my experience, on Amperex and Siemens, 6dj8 sounds the best, more air and warmth as well as frequency extension, compared to 6922 and 7308 version of same makers. 7308 sound the worst, bright, tinny, little harsh. And 6922 being in between 6dj8 and 7308. Funny thing is that 7308 is supposed to be the best in specification and 6922 is spec'ed for military use with long life compared to 6dj8. I guess best spec don't always yield best sound. On Amperex and Siemens, you can identify 6dj8 from 6922/7308 from their construction and date code.

One the other hand, Sylvania and Philips, both JAN 6922 and normal 6dj8 sound almost same if not same. Would it because they were all produced in same line but different label???