Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves Black Plates Copper Support Rods NOS-Testing

Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves Black Plates Copper Support Rods NOS-TestingThis new old stock testing matched pair of GE 12B4A tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 44 while Tube Two measured 48 where minimum (65%) is 32 and 100% is 49. Wish I could tell you how they sound, but I don't have any equipment that uses these. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY

THERE ISN'T

This hardcover book is in excellent / like-new condition

Wish I could tell you how they sound

I have played it in my Musical Paradise 301 MK 3 with an adapter (not included) as a 6SJ7 substitute and it sounds excellent -- airy with excellent dynamics and signal bandwidth

These two National Union clear bottle type / number 41 tubes tested as follows on our Paul Hart-calibrated TV7/U:

They tested (from left to right) as follows: 56

new in box Sylvania 6V4 / EZ80 rectifier tube tested to spec on Paul Hart-calibrated TV7/U

Tube One measured 47/44 while Tube Two measured 48/43 where minimum (65%) is 25/25 and 100% is 38

am showing both sides of the watch to make identification as easy as possible

5 record cleaner and then played them on my Rega Planar Three

new in box GE 21GY5 tubes tested to spec on our Paul Hart-calibrated TV7/U

The LPs themselves are in very good shape