MATCHED PAIR of early 1960's early production RCA 12AU7A / ECC82 type in original RCA boxes.
Generally held as one of the all time greatest versions of this tough, excellent sounding dual triode ... the clear top RCA .... they really are nice sounding and sport matching GM (transcondutance) performance! Both units test strong, no shorts and very QUIET. Checked in multiple testers and listened to by ear....great sounding tubes. Both units matched construction, big side D getters with thick & shinny chrome.
The 12AU7 is one of the most indelible, venerable audio tubes of all time. The 12au7's roots harken back to it's OCTAL based 8 pin progenator, the 6SN7 -- also a wonderful tube for use in any hifi or recording preamps. Dual triodes like this were used extensively from the mid 1940s, and have been useful ever since. Despite it's lower gain, the old-world design / performance of the 12Au7 -- it has persisted in all uses / and facets of audio. It's remained a perrienal favorite for hifi audio preamplification since the 1950s. It's once again making a strong comeback in the field of audiophile headphone amps -- in many cases providing enough gain for highly efficient speakers. Besides the 12Ax7 in fact, the 12au7 has been the absolute go-to choice for clean and quiet, stricly audiophile needs.
If you're shopping for a back up or replacement set of 12Au7 tubes -- definately buy vintage. The 12au7's workhorse characteristics kept it in production when many other tubes ceased. They were commercially available well through the 1960's into the early 1970s. Quality was high on this tube (espicially RCA & GE) , and it's fabulous tall plate design stayed much more consistent with little sound altering changes. Early 12au7's were tall plates, as were the last ever made, well into the 1970s. Likely one of the reasons they're sound is so consistantly nice.
The 12Au7 is a naturally quiet, and reserved sounding tube. Not at all bright or zippy -- ever. Over the years, listeners with otherwise dark sounding setups went searching for tubes with cleaner and clearer midrange detail. There have always been available excellently built cold-war industrial equivalents like the 5814 (GE made excellent ones, like the 5-star) and the triple mica types (5814,6189, and 5963). For audio use -- military / industrial tube #s are overbuilt. Popularized by tube dealers, selling off huge surpluses of mil-spec / industrial stockpiles. Industrial (5814/6189) versions of the 12au7 have been given OEM with high end preamps for years -- plenty of NOS stock -- and certainly better sound than any modern production from China or Russia. While industrial numbers have been plentiful .. .. the 1950s consumer / hifi / recording tubes is rare and dwindling -- supplies were not stockpiled by millitary or industry -- and listerners forgot what nicely blalnced tone and clear sound the consumer audio market's 12au7 / ecc82 delivers.
These ruggedized military communications / early computer switching tubes are cherished for long life, solid construction. Extra thick mica allowed them to survive shock, and thick filaments promised long on/off cycles -- yes mil-spec tubes were made to outlast the end of the world. Not always do they enliven music, as hifi use was never their intention -- and they sometimes sound too "black and white", or "hard and emotionless" -- sometimes even a bit harsh .. not always.. Some do, but many are great -- and this varies acorrding to the listener's circuit and tastes. Good Sylvania and GE industrial tubes are clearly worth trying -- but not before you first own good consumer / hifi / sound industry Recieving tubes, like the 12au7 / a / ECC82 -- buy vintage versions made by RCA, GE, also try Sylvania.
Back to these RCA Clear Tops .... in the photos below .. the RCA 12au7, starting production in the 1940's just after WWII was a 17mm black plate. They found broad use in all types of non military test equipment , VTVM meters, and HiFi, Studio Recording, Sound on Film / cinema sound. Many of the worlds most recordings were captured with mic preamps using 12au7 and 12ax7's in-circuit made by GE and RCA.
By the 1950's, RCA further refined the 12au7, which would be it's best revision known as the "Clear Top". Featuring nice 17mm tall grey plates, and a single side "d" shaped getter -- basking under brilliantly gleaming fully-flashed side. Over the years experienced listeners have ranked it consistanly in the top "5" best sounding 12au7's. Many listeners,declare it the best; bar-none -- beating out even the far more expensive, rare Amperex & Siemens ECC82 varients.
If you are looking for midrange clarity, without the inherent smooth darkness that you get fron Telefunken and some other European built models, these RCA's are a great choice. These tubes are a wonderful sounding, and will predictibly become one of your favorites -- absolutly worth adding to your tube collection.
Exhibit B, shows actual tube under test, dynamic emissions at full load for easy reference. Both tubes / all (2) sides read STRONG 115% of new.
They test (and sound) great, quiet and were GM matched (balanced) on a 2nd lab tester at full plate 250V.
Still in RCA boxes, they've been stored carefully for more than 40 years. Very old tubes, low hours , they have lots of life left. Just throughly checked using multiple testers and played with music. Working well; quiet and matched, detailed and sounding great! Guaranteed no problems. The most throughly tested, scrutinized and closest matching set of these you'll will see anywhere!
Getting very hard to find --- they will sell quickly.
These are the real McCoy. Dealers far & wide can no longer find early RCA's, as they haven't been made for last 50 years ++. And for guitar amps -- these are some of the very best tubes you can use ... and this PAIR; has incrediblely close GM, at full operating 250 volts eP -- .. they are also all very close dates of production, and at the start of the 17mm grey design ... very earliest incarnations .. and are bridging the earliest years of clear tops.... (RCA's first generation) with early 1960s 17mm plates which shrunk at the end of the decade. (see exhibit C,D).
Original red ink letters are mostly complete, and have only partial wear.. (exhibitB,C,D) ....Really beautiful tubes... flashing is very shinny & thick, likely NOS. They really present well. Strong and super quiet (no microphonics), no gas or shorts. They were carefully checked and played with music -- for full details please read the reports in exhibit B,C,D below, for test results.
Again, these are they are the early version of the RCA 12AU7A, aka ECC82 ... if you're collecting or planning to use in your old Fender, Gibson, Ampeg or hifi tube amp that calls for the ECC82 / 12AU7 / (A) --- here you go... probably the earliest & best matching set you'll see on here for a very long time - hefty grey ribbed plates and 1x BIG D side getter and super thick mirror flashing . With closely matched mhos & construction -- you just don't see'em like this very often. Study the included tube test results in photos and you'll see just how nicely fussed over, clean and well tested these originals are!
If you're currently a user of modern tubes then these will make a world of difference in your sound — a real upgrade and a treat for your ears -- clean, clear and more overall detail you can really hear.
Original tubes like this sell very quickly. Buy Now to avoid a bidder’s war.
Check my 100% feedback (check over what buyers have to say ... they love these vintage US tubes and I get allot of repeat customers ) ...always fast shipping, and always safe double box packing !!
100% happiness assured on all tubes and old audio items. Guaranteed NO DOA.
