TWO Amperex 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Tubes test at 10010 and 10350 where 6630 micromhos is pass/fail grade. Gm matched to within 3.5% difference. No rattle / tight base / no loose parts.
Item Tag: 7591 7591A
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TWO Amperex 7591A Tubes / Amplitrex Tested / 1978 World Globe Logo
TWO Amperex 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Tubes test at 9550 and 9800 where 6630 micromhos is pass/fail grade. No rattle / tight base / no loose parts.
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TWO The Fisher 7591A Tubes / Amplitrex Tested = Good But Not Great / Base Damage
TWO The Fisher 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Tubes test at 6950 and 8070 where 6630 micromhos is pass/fail grade. This is not great matched pair, but two good singles.
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TWO Amperex 7591A Tubes / Amplitrex Tested 💪 +100% / 1978 Dates / 2% Gm Matched
TWO Amperex 7591A vacuum tubes. Tested on Amplitrex AT-1000 tube tester (fixed bias mode). Matched 78-13 date codes = 1978 week 13. Tubes test at 10800 and 10940 where 6630 micromhos is pass/fail grade.