MATCHED PAIR of late 1940s/ early 1950's closely, matched early production RCA 6SN7 twin-triode tubes. Drop-in compatible replacement for most any circuit calling for glass or metal 6Sn7 type tubes.
This pair dates from around 1949-51.
Exhibit B, shows actual tube under test, dynamic emissions at full load for easy reference. Both (2) tubes / read STRONG 100% or more on all (4) sides , with good projected lifespan.
They test (and sound) strong, quiet and were current matched (balanced) on a 2nd lab tester at full plate ratings.
In original RCA boxes where they've been stored carefully for years. Very old tubes, pretty low hours , they have lots of life left -- from early HiFi estate. 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, closest pair of these you'll will see anywhere! Very hard to find They will sell quickly.
By the late 1940's just after World War II, RCA moved to the more rugged and robust, designs for the cold war. As Western Electric's influnence and technological leadership wained moving into the 1950s, RCA stepped in. Filling in all the gaps, leading in Commercial broadcast, recording and consumer receiving tube development. Altec and JBL remained leaders in the Cinema and Sound Renforcement, for loudspeakers and cinemas. In short, alongside Sylvania, GE and the smaller Tung-Sol ... RCA had the most experience in tube development.
The 6SN7, was born in a short era, post WWII, and just after wartime production of LokTal types ceased. It's an excellent preamp tube, and if your preamp utilizes the superior large type octal based series of tubes....you are in for a treat!
There are countless variations of the 6Sn7 tube, starting in the late 1930s and moving clear into the 1980s. Thankfully we have a few really high quality designs to choose from ...some of the best like these are "smoked" or grey glass types. The interior of the glass envelope's of these tubes, generally produced from the late 1940's into the height of the cold war 1950's era strike an excellent balance. They give great, smooth detail, while avoiding some of the harsher, communctions, ultra-ruggedized types like the Bendix RED-Bank.
These tubes, in many applications sound better than the more common 6Sn7 types. They and more detail, with alot of warmth, but no "fuzziness". If you are currently using modern production types (check your current requirements)... then give these a try -- you'll love them!
Dealers everywhere can no longer find these early RCA's, as they haven't been made for nearly 65 years. And for guitar amps -- these are some of the very best tubes you can use ... and this PAIR; have plates that are incrediblely close, and strong, and READING AS NOS at the full operating volts eP -- .. they are also all very close dates of production (see exhibit C&D for dates -- all early 1950s or 1940s), and at take end of the GREY GLASS era, (just before all 6Sn7's became clear!) design ... amongst the later incarnation of the 1940s redesign, and arguably one of the most perfected versions of this wondeful sounding twin-triode. This design begain in the late 1940s and stretched until end 1950s decade. (see exhibit B,C,D).
Cosmetics are good on these. Original boxes show some tattering and stains frm their many years. One of these tubes has a number scratched in it's base but this is very minor. These really present beatifully and have SILVER RCA letters in on black bakelite bases.. Strong , no gas or shorts. They were carefully checked and played with audio frequency -- for full details please read the reports in exhibit B,C,D below, for date codes and test results.
With closely matched plates & dates, and nice boxes -- 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.
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.