New in the original boxes.
Item Tag: 7591A
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TWO Amperex 7591A Tubes / Amplitrex Tested Above 90% / Within 3% Gm Matched
TWO Amperex 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Gm matched to within 3%. Tubes test at 9550 and 9200 where 6630 micromhos is pass/fail grade. 93.6% / 90.1% gm mutual conductance.
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(4) 7591 Sylvania U.S.A. Sansui Fisher Output vacuum tube valve
This item are 4tubes7591A Sylvania Made in U.S.A. Test result 70-75 min 36. Grey plate, O-Getter, Coin base, no original box. Used tubes.
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TWO McIntosh 7591A Tubes / Amplitrex Tested Approx 80% / Good Close Matched Pair
TWO McIntosh 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). The labels are very faded but the white “M” of McIntosh can be seen. Tubes test at 8370 and 8650 where 6630 micromhos is pass/fail grade.
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7591A GE brand International Coin Base Halo Getter Tested Pair Tubes Made in USA
Tested with AMPLITREX AT-1000 Tube tester MADE IN USA. Other test made Reboxed in our custom white box. Closing adhesive tape in brown paper – ECO-KRAFT. Brown paper sealing tape – ECO-KRAFT. TEST RESULT: VERY STRONG.
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TWO Amperex 7591A Tubes / Amplitrex Tested / One SUPER STRONG, Two Good Singles
TWO Amperex 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Tubes test at 11650 and 9690 where 6630 micromhos is pass/fail grade. 133% / 101.6% mA plate current. 114.2% / 95% gm mutual conductance.
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2x MatchedNOS 7868 GE USA PowerTubes/Fisher Bogen Ampeg /Like 7591A w/Adapter
+ ampeg conn scott sherwood pilot sansui kenwood pioneer eico harmon gibson and even seeburg jukeboxes incorporated these. these oe boxed ge usa classics are collectible for their sound, long tenured history, and top build quality (see their 5star series!).
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TWO McIntosh 7591A Tubes / Amplitrex Tested /Strong Plate Current/Close Gm Match
TWO McIntosh 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). 85.6% / 86.8% gm mutual conductance. Tubes test at 8740 and 8860 where 6630 micromhos is pass/fail grade. Tube 1: 8740 micromhos @ 60.6mA plate current emissions.
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Sylvania 7591 7591A Excellent Testing Values Matched Quad
The tube was carefully tested on my TV-7D/U at 68-70-70-72/36 min good (55-56=100%). They all sound wonderful on my hifi system. Super rare and hard to find now.
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Amplifier 7591 7591A Vacuum Tube Tester V8 Bias Current Checker Octal mA Version
Octal 8pin probes cable lengh: 55cm. 4pcs Octal 8pin Bias Current Probes. A separate resin board is used at the top. Prevent short circuits making readings incorrect. 03: Then plug V8 tester probes in amplifier socket.