You very rarely such a nice matched pair of these WWII "wartime" smoked, grey glass 2A3 triodes ... we have here a balanced, matched plates and GM, scoring around 56~57ma iP @ 5000 mhos @ fixed bias 250V on a calibrated AT1000 tester.
These tubes tested nice and strong on our Dan Nelson calibrated Tv7 at 80 and 82 (Tv7 minimum = 38).
(In the old times, 1970's & 80s before the TV7's military minimum (which equates to about 70%) score was understood worldwide, Tv7 readings could be converted to "percentage" by the multiplier of x1.89, giving both of these gently used triodes a reading of around 140% of each.
They look and perform as strong / low hours with original prewar, slightly tattered snug slip over sleeves that verify the 70 plus years of age.
As these very early tubes warm-up, which is a little longer compared to newer types, you'll hear the normal creaks as the "hung filaments" heat up and adjust and expand to their suspension.
These are original production, and about 74 years old ... don't settle for modern 2A3’s -- these are terrific sounding -- the real McCoy. Old tubes sound better (proving the old maxim .. you get what you pay for! )
These Ken-Rad tubes are prewar style, with "hanging filments". Along with beauty of old world design, you can expect terrific realism and detail from 2A3's like this -- very smooth too. Unacquainted owners of prewar style tubes should be aware, that along with the detail, these tubes are not as resistant to mechanical vibrations, and therefore not as absolutely quiet as more modern coil-sprung filaments. A small price to pay for the great sound, these "hung" filaments are the same style you see on early versions of Western Electric 300B's and many other the other famously good sounding big old DHT's.
They have authentic etched - in - glass "stop sign" 2A3 letters as well as silver Ink markings all along the nice, tight bases. These tubes are beautiful. filaments, which both perform nicely. Sometimes can be seen, an unusual uneven illuminaton pattern (one side of each tube appears, at the very top to be less bright) -- this is a 100% normal condition, from factory like this and these tubes still perform flawlessly, and strong -- they sound nice and are guaranteed No DOA, to arrive working well.
These are the real originals, made in the USA during the mid 1940s. right around the close of WWII ..the 2A3 was by then a very mature tube, still manufactured for early production HiFi amps like the Brook, and other exotic high fidelity consoles like Caphart of the late 1940s, and for the prewar amps still in service of the 1930s, many of which were still operating all across North America well into the late 1950s/60s. Manufacturers like RCA, Sylvania, GE and Ken Rad and Tung Sol had perfected their build quality and performance of big triodes during this time, though not many were sold. Matched low hours 2a3’s are tough to find, so these will sell quickly.
Kentucky Radio or Ken-Rad of course was it’s own manufacturing company back then, and we're pretty certain these were made by the company in their own Kentucky factory.
They do bear the “stop sign” letter etching., which makes me wonder, still Ken-Rad in particular was known to use the same marking. While it’s possible they are RCA’s or GE they are still very early and just as excellent.
Sometime in the 1950s, General Electric, (whom Ken-Rad was an OEM supplier) bought the Ken-Rad factory, as they lost mountains of money developing their own early verison newly developed minature 12AX7 tube line. GE operated the Kentucky plant for many years thereafter. Ken-Rad was a very high quality outfit, and the tubes sound really nice and different from the “big three” types usually. These are from a brief period, right after WWII, when they were still producing tubes with the “smoked, grey glass” process, which is a type of inner getter material to help with longevity.
Real, early tubes like this are a treat to find. They were, one of the most unique tube designers and manufacturers. Most of the time they built 100% in-house, by their own employees and rarely crossbranded, a practice common to other companies. Unlike the other major competitors (GE, RCA, Sylvania) --
Audiophiles have long appreciated Ken Rad and GE tubes from one of the USA South's few tube factories ...and you are guaranteed some of the best build quality. The nice and usual, exceptional musical performance is a treat -- always pleasingly different and often times better than other USA brands of the era.
I get allot of requests for 2A3’s like this.... (from owners early globes and mono plates, looking for reliable workhorse 2A3’s to use daily, for instance). If you are already in love with the other major 1940s & 50s USA brands, like GE, RCA & Sylvania ... don’t deprive yourself of the seldom seen Ken Rad / GE types. … you won’t be dissapointed … and they deliver the goods. If you are looking for the same amazing detail and build quality; something refined and different ... look for 2A3's like this from the 1940s are the best years.
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