The 'Adaptive Autobias' of PrimaLuna's new EV0 300 tube integrated amplifier allows the owner to use any of the following output valves:
6L6G; 6L6GC; 7581A; EL34; EL37; 6550; KT66; KT77; KT88; KT90; KT120; KT150
Changing tubes to tweak your sound must be infinitely preferable to tone controls, graphic equalisers or experimenting with cables!
I can confirm it, I have 3 different sets of tubes and added to the triode / ultralinear mode selector I enjoy six different types of sound. That said, I must clarify that the Auto Bias is not exclusive to the Evo line, I have a PL Dialogue Two (already discontinued model) with that great technical advance, although some do not assign it the importance it deserves .....