I think I have found the End Game Amp

2A3 not the best pair up with those inefficient Rockports

There is a misconception that all amplifiers given a tube spec are the same, and that makes as much sense as saying all 50 wpc solid state amplifiers are the same. The quality of the power supply makes more of a difference. Similar to when someone comments that all 300b amps have poor wooly bass, they obviously have not heard a good 300b amp. 

I fondly recall giggling like a small child the first time I felt my walls shaking from my 4.2 wpc 2a3 amp (98db efficient 4 ohm speakers). I am pretty sure my 100 class A watts per channel Coda 15.5+ does not shake them any harder. 

I have tried a variety of pre amp & power amp combinations over the last two years and the current setup, though perhaps unconventional, is yielding the best sound, based on my desired qualities and music preferences.  I realize that the setup is "at the margin", SE 2A3s and 300Bs did not quite handle orchestral works.  Solid State was not beautiful, powerful PP tubes (KT 120s) sounded good (indeed the C-J amp was very good) but did not quite have the magic of superbly executed PP 2A3; yes, Mahler’s timpani had more slam but the beauty of the human voice, and the sense of space, in liturgical works, was not quite there.

Proof is in the pudding. You know when you know. 

@posbwp55 Thanks for the article.  I read it through and it seems to (just) validate what I hear on theoretical grounds.

I mentioned that I measured the SPL at my listening position at 84dB with 2 watts (2.83v).  14 watts yields an additional 8.45 watts (theory) and in practice 92 dB is about my comfortable peak for orchestral stuff.

At the bottom end pp passages are at 65db, do a dynamic range of 27dB - in line with the article's 26 dB range.

So, yes, the power is marginal at the upper limit but the SQ in the middle is sublime.

@mclinnguy No, I cannot shake the walls at 92 dB, but I live in a log home and it would take a bulldozer to move them anyway!

Most of the time I am listening in the mid 70dB range - .5 watts.

Regarding "wooly bass" and 300B amps, for many years I had a VAC Ren 70/70, driving Audio Physic Virgo IIIs.  Than could do excellent bass!

As long as you don't require head banging volume, a pushpull 2a3 amp can be used with somewhat inefficient speakers.  I think most people greatly overestimate how much power they need or put too much emphasis on the ability to play at extremely high volume even though such demand requires a lot of compromise in the ability to play beautifully for the vast majority of the time.  I am a big fan of low-powered tube amps.  I own a parallel SET 2a3 amp and a pushpull 349 amp (5 watts per channel).

Retired audio guy,

It seems you value a beautiful midrange presentation as your highest priority. Let me recommend the 6SN7 that is the king of beautiful midrange presentation, that tube is the Brimar black glass 1988 labeled tube. They are expensive but they are special in midrange presentation. If you primarily listen to choral and string quartets type classical, you may value their presentation.

@posbwp55 yes, a beautiful midrange, but also a sense of space & air.  This seems to be what 2A3s do better than any other tube.  300Bs don't quite get the air of the 2A3s.  I'll keep an eye out for the Brimars, currently I am using the smoked glass RCAs in the critical preamp gain stage.

In my analog setup the cartridge is the Koetsu Rosewood Signature Platinum with a mid range unsurpassed, and the Dos Locos brings out its best.

@larryi The Rockports are really average sensitivity, there are many much lower than 87.5, and they really do show what everything else in the system is doing, utterly transparent; I think that you cannot get that with "high efficiency" speakers - I'm probably going to get taken apart for saying that.