Matched Pair General Electric GE 6SJ7 6J8P Vacuum Tubes NOS-Testing 9002 Septal new in box US-made 6F7

new in box US-made 6F7 tubes tested to spec on our Paul Hart-calibrated TV7/U

These tubes have copper support rods

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

It measured 42/49 where minimum (65%) is 50/50 and 100% is 77/77

dynamics and frequency response

Matched Pair General Electric GE 6SJ7 6J8P Vacuum Tubes NOS-Testing 9002 Septal new in box US-made 6F7This new old stock testing, perfectly matched pair of GE 6SJ7s was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 77 for both tubes where minimum (65%) is 40. They have 56 26 188 4 and 61 26 188 4 date provenance codes, respectively. I am playing them as I write in my Musical Paradise MP 301 MK3 and they sound excellent. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES.