Primaluna?

I have a PL EVO400 amp.  Best amp I’ve heard, and I’ve owned a lot.  True balanced, single ended, auto bias, 4, 8, 16 ohm taps.  Can be used as a stereo or mono amp. Uses any tube you put into it. El34, kt88, kt120, kt150, etc.  Incredibly great sound, non existent noise floor, triode, ultra linear.    Sounds like silk.   What’s no to like, come on man!

I have two friends that own Fisher 500c receivers. They have auto bias, so no, that's nothing new, but that's not a bad thing. Both units are still working flawlessly and sound pretty good with Klipsch speakers.

Primaluna has 'adaptive autobias'. So not at all the same thing. So many people here like to say autobias has been around forever. But it's not the same animal.

Try putting a kt150 next to an el34 and every other kind of tube in between. Can't do that with other designs. Look at the autobias boards in a Primaluna...not the same animal.

Every design is a compromise...Primaluna gets you close enough to the best but makes concessions to reliability. It's one of the reasons I went with this brand. After a bad experience with a Don Sachs Kootenay, I decided that I didn't need the drama. The Kootenay sounded a little better when it worked. 

In my room I've only had BAT but wonder about how it'd compare to PL, ARC, and especially Rogue.  Yes replace all the tubes at the same time, else your mind will devour itself when you start hearing things that don't quite sound right.  Best feature not explicitly mentioned above is 3 sets of taps to match diff't speaker impedances.