Sylvania 7F7 Vacuum Tube

Sylvania 7F7 Vacuum TubeThis Sylvania 7F7 was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. It measured 42 44 where minimum (65%) is 33 33 and 100% is 51 51. I have played it in my Cern Audio phono pre preamplifier as a 6SL7 substitute (with an adapter, not included) and it sounds outstanding. It is dead quiet when the preamp is muted and has excellent frequency response, sound staging, and dynamics It is somewhat

This Moss Music Group DBX pressing has no surface noise but a very few pops and ticks

Enhanced Cooling: yes

gold pin E81L / 6686 tested to spec on our Paul Hart-calibrated TV7/U

where minimum (65%) is 36 and 100% is 56

52 and 59 respectively

side-D getter and is boldly stamped "Dominion Of Canada

63-29 188-20 date/EIA codes

The 7189 is a more robust EL84 which is able to dissipate an extra watt or two

This is an early-production 12AU7

gray ladder-plates

This pair is not recommended for push-pull as their plate current draw is too unbalanced

This new old stock-testing matched pair of National Union-MANUFATURED Type 37 triodes was tested on our Paul Hart-calibrated TV7 For shorts