I do not have any test equipment unfortunately. Its just what i hear. He did gave me some test results. Tube #1 (01.1975): Ia1 = 11.0 mA; Ia2 = 12.0 mA; Tube #2 (06.1975): Ia1 = 12.0 mA; Ia2 = 11.0 mA; So far the tubes are a big improvement over my 1971 siemens. They are clear and spacious, detailed, with a hint of warmth.
8/23/16 at 8:21am