Having heard NATs drive apogee full range mids and Dartzeel drive evolution acoustics MM7 and having seen, for the first time, the cumulative effects of low noise and headroom succeeding to produce a better of everything, I am now a complete advocate of SS power amps except on horns. Unfortunately at the budget many are at, the SS is too crap and at small room sizes where large scale music cannot be played, valves sound better, and if the room is not well treated and well planned, you need valves to give that decay which SS might lack. Sorry for short and possibly vague message but too much to catch up on after a West coast weekend
What about instrument tone, microdynamics and solid 3d imaging and soundstaging? Based on what I have heard from darTZeel it cannot do natural tone like a good SET. Like good SS, for sure. I think Michael Fremer's review where he compares the big darTZeel to the top Lamm ML3 illustrates and despite the fact that Fremer bought darTZeel, he had to admit what the Lamm was better at doing. Read the two reviews...the darTZeel is all an analytical description and the Lamm is a description of something approaching the living breathing music. The Dart review is all about speed, attack, resolution...oh and the tone is not so bad. The Lamm is about how real it sounded and how it shocked listeners to attention with that instant recognition of the real. I don't know about you but my quest is for the latter and not the former...clearly Fremer goes more for the analytical...maybe because it makes him a more "serious" reviewer...I don't know but his systems have always leaned that direction.
I have only heard the big ones under show conditions (the small ones I heard at length at Herve Deletraz's place with Dart pre) on Marten Design Coltrane Supreme 2s. It was not an impressive showing for the big system despite the enormous cost.
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The Lamms gone, I reconnected the big darTZeel NHB-458 monoblocks ($144,500/pair) and, after letting them warm up for a day, played the track again. Through the solid-state amps, the sprinkly chime was still fast and precise but somewhat more harmonically reserved, and less three-dimensional and lifelike. But the double bass was definitely more like what I'd heard live, with greater control and authority, a tighter physical presence, and better delineation of the instrument from the reverberant space. All of which was also true of the trumpet: a bit less bloat, but a slightly drier sound. The hall and the instruments in it were also pushed somewhat farther back from the listening position than they were through the Lamms.
A strong case could be made for the verisimilitude of the sound from either of these pairs of similarly priced amplifiers, but the award for mesmerizingly hypnotic sound must go to the Lamm ML3 Signature.
Read more at http://www.stereophile.com/content/lamm-industries-ml3-signature-monoblock-power-amplifier-page-2#ZZq54Uftqp1kzSLA.99"
Its this kind of description that convinces me that the darTZeel is not the sound for real acoustic music in space and is more geared towards an analytical rendition...at least compared to a top notch SET...against other SS amps it is likely to be better than most.
"The ML3s sounded far more linear overall, especially at the bottom, though not as linear or as well controlled as the darTZeels, but it was close enough to call it a trade-off: the tube amp provided greater textural and harmonic detail and, especially, a more fully fleshed out midband; the solid-state amp provided greater bass control and dynamic thrust, and a bit more extension.
Read more at http://www.stereophile.com/content/lamm-industries-ml3-signature-monoblock-power-amplifier-page-2#ZZq54Uftqp1kzSLA.99"
Again, as to be expected; however, I would note that based on the Lamm's measurements, I can fully understand why the bass is lacking somewhat in slam and control.
http://www.stereophile.com/content/...er-amplifier-measurements#Vx6u2mZD7hh5U1Tt.97
Note Figure 11 and 12. There is some core saturation in the output transformer that is likely responsible for a bit of "loosness" in the bass. I haven't seen measurements for the Diana but I can imagine that it does not have this rise in distortion at low frequencies because it has grip and slam like a really good SS amp but tone and texture like a true SET. Lamm could have used a bit bigger core on their output transformer and avoided this problem and had better bass. However, that would have required redesign in other areas, like the winding, to get good HF extension still. So, the Lamm then is maybe not the best SET in the world as it still have some measureable flaws that could have been corrected...especially at this price range.