2x TESLA ECC802S / 12AU7WA. of original TESLA ECC802S tubes. These are industrial-grade tubes made for army or aerospace use, and other demanding applications. PROTOTYPE SERIE! Tube 2: Ia1=2.90mA / Ia2 =3.00mA, S/gm1= 1.00 mA/V / S/gm2= 1.05mA/V.
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