Difference between Lorenz and ITT Lorenz 12AU7?
My understanding is that the traditional Lorenz 12AU7 was made in Germany but that some tubes labeled Lorenz were made in eastern Europe (ie Hungary). Did Lorenz make their own tubes or were they made by, say, Siemens for Lorenz? Both? And what is the distinction for "ITT" Lorentz? Also, generally speaking: What is the most detailed and holographic NOS 12AU7 out there? The best I've found so far are early Amperex/Hollard long plates. Do any of the 12AU7 analogue tubes (ie 5814) improve on its performance?