Mullard EF86 6267 Mesh Plates Matched Pair Brimar Label Blackburn 1961 NOS

Model: Mullard EF86 6267 (Made in United Kingdom). Lush and warm vintage tone, intiimate vocals, wide sound stage with layered details. B 1 B (B = Blackburn, 1 = 1961, B = February). GM (Mutual Conductance) test result : 100%/105% NOS.

Packaging : NEW white tube boxes. NO shorts, leakage or gas. The two tubes tested Strong (80%+ mutual conductance value for NOS/NEW) on a reliable Mercury 2000 tube tester with the following result mutual conductance both in. UMhos and in percentage of NOS/NEW value.

Tube 1 : 2,000 (100%). Tube 2 : 2,090 (105%). Good tubes start at 1,200 and new tubes incl. NOS/NIB 2,000, and the Mercury 2000's rated mutual conductance for new EF86 tube is 2,000.

Test result can also be seen in the pictures. In case you wonder what all these numbers mean to your sound experience, it's actually quite straightforward: mutual conductance directly translates to a tube's ability to amplify sound , so the higher the numbers the better.