2x TESLA ECC83 / 12AX7
You are bidding on 2 pieces (matched pair!) of *original* 1958 TESLA ECC83 tubes.
They feature foil disc getter on a large and robust support, smooth folded plates, non-corrosive pins and yellow prints.
One tube has a military 'crossed swords' marking!
100% guarantee original Tesla, NOT JJ, not re-branded RFT.
Tube 1: Ia1= 1.70 mA / Ia2 = 1.90 mA, S/gm1= 1.40 mA/V / S/gm2= 1.50 mA/V
Tube 2: Ia1= 2.00 mA / Ia2 = 1.90 mA, S/gm1= 1.60 mA/V / S/gm2= 1.50 mA/V
...where a new/unused tube should have around S/gm = 1.60 mA/V, "good" value for transconductance starts at 1.2 mA/V.
Close date codes: 11-12/1962
Extremely high quality audio tubes for hifi/high-end/guitar amplifiers.
Combine shipping is possible !