Model: 1961 Mullard 6080WA (Made in United Kingdom). Lush and warm vintage tone, intiimate vocals, wide sound stage with layered details.
Date codes: AJ1 B1F1 (AJ = 6080 production, B = Blackburn, 1 = 1961, F = June, 1 = Week 1 of production month). GM (Mutual Conductance) test result. This set was tested and certified by RoeTest V11 tester with the following result.
Measured transconductance (GM): 7/7.38 mA/V - 106%/112% (100% = 6.60 mA/V). Measured plate current (IA): 114.92/111.84 mA - 115%/112% (100% = 100 mA). NO shorts, leakage or gas. Curve trace is also included in the original RoeTest report.