Well, just to prove it's all different. . . I really like the sound that Steve has gotten out of the EL34s in my Monoblocks.  The overall signature is very very much like the Select I had for years, but. . . more power and perhaps a bit less etched, two things going for it.

Gee Terry, in the overall history of domestic tubed gear, I think you'll find the EL84/6BQ5 is not so much intentionally overlooked, as simply unseen.  

While it's easy for us to consider only separate components featuring the devices you mentioned as serious audio gear, there are probably more hidden treasure SET & SEP chassis lurking under the skin of the parent's stereo console, Grundig mantle radio or Aunt Bessie's electronic organ than we can count.  Based on the satisfaction that many of us have obtain recycling these organ donors, which even with minimal parts upgrading can deliver stunning bang for the buck, the power amp stage of many of these systems was not the weakest link - that Garrard stacking record player with Astatic crystal pickup however ......  :-X


I'd also wager that more than a few "newer" designs are based on some of these 50yr old circuits.

There's nothing transcendentally magical about the SV83 device itself, or the "glamour girls" 2A3/300B, etc., or even SS devices as heard in the latest generations of digital amps,  all of us have heard underwhelming systems using any of these.  

All real world (i.e. affordable) audio gear is a balance of acceptable compromises, and Steve's implementation of the Zen series is quite crafty; as indicated by a number of posts throughout  the history of this forum, other designers or tweakers would make some different decisions -  but as anyone who has heard the amps will affirm, it's the results that count, and there's no question these sing for themselves.