Up for sale is a rare vintage NOS Brimar CV4006 / 6067 (12AU7 / ECC82 equivalent) high-grade dual triode vacuum tube, packaged in its original British military government box marked “Valve Electronic 10CV / 4006” (KB/AD code). The CV4006 is the ultimate military-spec, shock-resistant version of the 6067 / 12AU7 series, constructed with an ultra-rugged triple mica spacer system to eliminate microphonics and a robust silver / bright plate structure with a classic big ring getter. Sought after by high-end audiophiles for its exceptionally wide soundstage, sweet dynamic midrange, and military-grade durability.

As shown, the tube has been thoroughly tested on our laboratory-grade Amplitrex AT1000 tube tester operating in full fixed-bias mode. Plate current ($Ip$) and transconductance ($Gm$) measurements alongside percentage performance ratings relative to nominal factory specs are detailed in the table below.