National Union NU 813 Vacuum Tube

National Union NU 813 Vacuum TubeThis National Union plate 813 output triode was tested on our Paul Hart calibrated for shorts, gas and transconductance. There were no shorts or gas. It measured 64 where minimum is 40 and new is 74. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING

64 and 70 where minimum (65%) is 49

These tubes have great bass and sparkling highs and Pete Ham's voice is warm and clear as a bell

but this does not affect performance at sound pressure levels far above normal playback even though the speakers are on the same equipment rack

It measured 56/52 where minimum (65%) is 40/40 and 100% is 62/62

I am playing them as I write in my Alan Eaton single-ended 45 amplifier with RCA Living Stereo's CD of Bartok's "Concerto For Orchestra

It is dead quiet when the preamp is muted and has excellent frequency response and dynamics

" Tube one has a brown base and 59-43 date codes while Tube Two has 1-17 date codes and a black base

This tube is new old stock and new in box and is sold as-is as I could not find a setting for it on our TV7/U

Date Codes: 1-43 and NK

steel support rods and gray plates

The spine is in fine shape with no loose pages and APPEARS to be leather-bound

This Sylvania 5Y3GT black plate rectifier tube was tested on our Paul Hart-calibrated TV7/U for shorts