Matched Pair Amperex 6BL8 Vacuum Tubes Valves 7199 Substitute New Sound Of Los new in box 12FM6 tubes

new in box 12FM6 tubes tested to spec on our Paul Hart-calibrated TV7/U

25 watt precision resistors new old stock

new in box GE 6HB7 tubes tested to spec on our Paul Hart-calibrated TV7/U

they were very brittle

This new old stock-testing almost-perfectly-matched pair of Sovtek 6BQ5 / EL84 / 6P14 / 6P14P output tubes was tested on our Maxi-Matcher 2 -- with 325 volts on the plates and a bias of -14 volts -- for shorts

Matched Pair Amperex 6BL8 Vacuum Tubes Valves 7199 Substitute New Sound Of Los new in box 12FM6 tubesThis matched pair of French Amperex 6BL8 pentode triode tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 38 39 for Tube One and 41 35 for Tube Two where minimum (65%) is 34 36 and 100% is 52 55. As I write, I am listening to them with adapters in my Dynaco Stereo 70. They make excellent 7199 substitutes and sounded great in my amp. They were played with