A vintage, matched, strong, NOS, new pair of WE 422A rectifier tubes.  This pair tests over , all sides, 120% of new condition , inspected on both a calibrated TV7 & JAckson 648S at full load (see exibit B and C). Life tests were that of new, nos tubev( 125% unpon filament drop on all sides). 

Perfectly matched pair from March 1968. The 1960's era of these tubes were still at the peak of WE's quality , dark-- and getting quite scarce. They feature 30mm tall, heavy grey (rather than the later black) plates, with 6 weld spots, and are the last early production of the 422A. The 422A was introuduced in the late 1940s as a potential replacement for the aging 274B. It found wide use throughout the the Bell System -- one of WE's most reliable and long lived rectifiers. 

Pairs of so closely matched-date 422A's are somewhat rare to see, and plates are matched as well -- according to both calibrated testers (see Exhibit B & C) making this set a superior buy -- they'll sell quickly for this reason. If you need a set for your mono block amps, or want a strong one to use along with a backup, this is one of the best pairs you'll ever see -- and they the old ones, in orignial boxes.  They are NOS, from Bell System surplus.

Cosmetically superb, there are a couple of minor flaws... one tubes has incomplete  yellow letters and bases from the factory nearly 50 years ago when printed. Tube #1 has a few white specks, whcih was common production flaw for the 422A, and is unimportant --cosmetic only (See pointer in exhibit I).  Tube #2 has a slightly loose mica spacer. Again a very commonly see in production of the 422 -- the construction of ST must allow for slight expansion when heated for many hours. WE design intended this -- sometime there is a slight movement when tapped hard with finger only at top --- this does not cause any trouble -- it's a QUIET tube -- perfect function -- no shorts.  Cosmetic issue only, (see exhibit  . Tubes are otherwise pretty perfectly matched and with exact test performance and construction (see included reports below Exhibit A,B,C,E,F). 

These are beautiful tubes!  Included are their original WE boxes with cotton excelsior packing. Both tubes tested twice on calibrated testers -- each tube tested like new! TV7 reported  59/59 where the minimum value is 40 -- and 120%/120% per side ++ on a calibrated Jackson 648 at full load. No shorts, or gas. -- verified NOS / NIB level performance.

The WE 422A may be the best ever 5U4 upgrade design - it's a direct plug-in for most later 5U4's with octal bases. It is not a plug-in for 274's or early 5U4G's because their bases are different even though the 422A will work fine with a base converter. These are of excellent vintage construction...heavy grey plates, 2 x side getter,tight bases and bright yellow print ... 47 years old .. Bell System, the real McCoy! 

 Simply one of the best recifiers ever made, even compared to the WE274 A/B. These will sell quickly as they are very hard to find ... and in the past 5 years they've approximately doubled in value.

Upgrading your amps rectifers really does make a big difference in sound. I favor these over every 5U4 varient except 274A/B! If you can use 5Z3 I also like early Cunningham and Sylvania green leaf -- still the 422A is simply in a much higher league!  

 When compared to most regular 5U4's .... the 422A brings amazing focus, allot of detail and a tight, clean bass.  These beautiful tubes are Guaranteed no DOA. The 422A is so useful, it's fairly easy to predict, with continued trends it will be double again in value after 10 years.  Truly great sound, one... if not the best octal base rectifiers we've ever heard in our WE 91 SE amps.   Comes with a BSP tube spec sheets as well as the sheet for the 422A.  100% safe packing in TRIPLE box.