You rarely see them.
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2x TESLA ECC802S / 12AU7WA. of original TESLA ECC802S tubes. These are industrial-grade tubes made for army or aerospace use, and other demanding applications. Datecodes: FY = 6/1974. Tube 2: Ia1=3.50mA / Ia2 =3.80mA, S/gm1= 1.25 mA/V / S/gm2= 1.30 mA/V.
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12AU7 ECC82 PREAMP. These tubes are perfect in every way matched and balanced. They are very honest in all frequencies. Perfect mids with near perfect vocal presentation. The bass is punchy and not muddled in any way.
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Tested NOS on my AVO mk4 valve tester as follows.
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These are industrial-grade tubes made for army or aerospace use, and other demanding applications. Both tubes are mint, evidently never used. Boxes were disinfected. Both tubes test as NOS/100%+ 100% gm/S = 1.0 mA/V, 100% Ia = approx.
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2x TESLA ECC802S / 12AU7WA. of original TESLA ECC802S tubes. These are industrial-grade tubes made for army or aerospace use, and other demanding applications. Datecodes: FW = 4/1974. Tube 2: Ia1=3.70mA / Ia2 =3.60mA, S/gm1= 1.30 mA/V / S/gm2= 1.25 mA/V.
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I can provide a large number of spare parts for old PCs.
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