The noise figures, matching and gain of the New Sensor ‘reissue’ 12AX7 are certainly adequate for purpose, that is being used in a guitar amp, it’s a good tube, but it isn’t a Mullard ECC83. The Mullard is a superior device from a bygone era when tubes were manufactured not only for audio but for use in other, more demanding applications such as ruggedised military gear and laboratory instrumentation. From the test results it seems reasonable to conclude that the ‘reissue’ is just a graded Sovtek 12AX7LPS, however a full and detailed dissection of both tubes would be required to absolutely confirm this. There’s nothing unethical with grading and paying additional coin for what appears to be a premium Sovtek 12AX7LPS. In fact, I’d think more highly of New Sensor if they stood by their own brand name and marketed this tube as a premium Sovtek 12AX7LPS rather than using the Mullard’s logo to distance themselves from their Russian roots – the association with Mullard is just plain wrong in my opinion. There’s no heritage, no link at all with the engineering expertise and no use of the original tooling or materials.