What is the magic behind SET

Here is my journey:

I started out with Cary 300B SEI 5-6 years ago, but my speakers were not good match for them. I ended up going to an all Levinson Avalon system for a few years. I was never quite satisfied with that system. It did all the technical things right but I could not enjoy it for various reasons.
Anyway, I ended up switching to a home theater only system.

A year or so ago, I decided to try out SET again in the bedroom ssytem, but first thing I did was to find some efficient speakers. Coincident Triumph UHS were the only speakers that fit in the bedroom and 92-94dB efficent/high-impedance. (My wife would never allow horn speakers in the master bedroom) Then I tried out an ASL Orchid 2A3 integrated. It sounded great but it always runs out of power with rock/symphonic music. 3W/ch is not quite enough. So I switched over to a Dared 845 SET integrated. Rolled a few tubes. Funny, this is the most musically involved system I had in the last 10 years and it did not cost $40k.

My suggestion for SET game is:
1) Find the speakers that you like. Flat impedance curves > 4 Ohms is most important. Efficency will mater if you have a mid to large room.
2) Match the amp output power to speaker accordingly. The power output requirement will determine the type of tubes you can live with.

It has the magic in front and back and left and right. That is whats behind the SET.

Some designs utilize transformers to couple the driver tube to the output tube which eliminates any capacitors in the signal path. With very, very good transformers this is about as close to "straight wire with gain" as one can get it would seem.

Indeed, my Moth Audio Si2A3 is just like that. Input wire to driver tube to output tube to output transformer. Nothing else in the signal path and its very sweet.

C123666, are these the interstage coupled amps you referred to in another thread? Could you guys list a few? I'm very interested. Thanks!