Matched set of the revered General Electric JG-5814A from the late 1950s --- known as the "Triple Mica". Unique extreme build qualities makes these one of america's most rugged 12au7 ever designed. They outperform almost every other type of 12au7/A / ECC82   

The GE 5814 which debuted in the late 1940s just after WWII, designed to withstand the shocks of war and extreme industrial demands.  The most rugged version was the late 1950s Triple Mica design, featuring a double braced getter support. Amazing build construction. These tubes featured higher than normal transconductance (usually), extended filament life and extra mica layers. Technically the GE 5 Star series does have a triple mica build, while this version, the JF 5814 does. 

This is an identical,matched pair of 5814A  -- made mid/late 1957.... hard to find this clsely matched, in build and in performance (see exhibit A,C,D,E for reports below)  They feature early 1960's construction , this design all  spaned from 1963 to about 1970....!  These tubes have original torn, brown military boxes, in which they were stored (they show wear dirt from the many years) 

For easy reference, refer to exhibit ( B ), these tubes are strong, testing 120% on a Calibrated Jackson 648 at full load,  all halves, (8) sides of the triode. Projected life on these is excedeingly excellent. 

Comparing to the 12Au7(A) refined short & box plate is interesting. The JG-5814A is a truly beautiful tube. The heavy, deep red filaments glow intensely through lower area. Something to consider if your application is visable. -- They too have strong ( techinical) qualities ...they're rugged, sound incrdible nice , detailed, open and smooth with more depth than other industrial # dual triodes. While the 12au7A is a pretty quiet tube .. the 5814A is quieter! Depending on your listening habits and equipment, you probably don't need such extreme specs -- still it's nice to own such amazing pieces of engineering, and qualit in your collection.    Under extreme vibration, on a shaky floor or humming transformer .... and hard usage are these are far more resistant to noise. 

Traditionially the principal King in this arena are offerings from Mullard and Siemens of the 1950s (and certain other expensive and delicate Amperex types). The GE is easily able to beat some of these. Especially if you need more midrange prescence. 

These days, smart, internet educated audiophile hobbyists have left by the traditional European favorites to discover the rugged & satisfying quality of the USA's golden postwar tube production era. The vintage American tone can't be duplicated. You get crisp, bold midrange, with a smoothness and warmth, all in one package.  These tubes are tops for vocals and instruments alike. 

To experienced listeners, this era of General Electric's tubes are really among the finest sounding the USA ever produced. General Electric made some of these tubes at the (formerly Kentucky Radio) plant in Owensboro Kentucky. This factory produced some of the earliest 12A*** type mini tubes beginning in the late 1940s....moving to shorter pates sometime in the middle 1960s ... to meet newer Cold War design requirements. These mid 60s  production GE are a criterion standard,  absolutely have signature of all General Electic production... featuring etched-on-glass letters in glass with the dot code.

 They without doubt have the quintessential sound of early 1960's america -- very BRIGHT & CLEAR accurate tone and not shouty, and not edgy -- after hours of warm up, the detail really shines and you'll wonder how you've ever lived without quality of these GE's!  Study all exhibit photos below...you will find this to be one of the nicest matched quads online and anywhere.

.. tubes that last as long as these will serve you well! They test strongly and will provide many hours of enjoyment ( depending on your habits, you may even pass them along to your children!) 

As shown, this special offer includes (2) test strong, excellent low hours JG- 5814A, triple mica... 

 ALL TUBES Guaranteed NO DOA