Wanted to share a recent experience...
I have owned a PrimaLuna DiaLogue One for more than 6 years at this point, and absolutely love it. It was the bargain of the century and a real gem of an integrated. It is, in theory, an EL-34-based amp, but many other power tube types are compatible and tube-rolling is more than encouraged by both the manufacturer and the actual design of the unit. I have tried many different choices with it, but have settled with a quad of the new re-issue Gold Lion KT-88's, which after many a back-and-forth, I find offer the best possible balance between finesse/midrange magic and dynamics/control. I am actually using the DiaLogue One with Sonus faber Elipsa SE's (or "Red"), and, amazingly enough (and after a rocky start as the speakers were breaking in), the synergy is pretty great! Plus, I have a small room, so dynamics and slam are more than sufficient.
At one point I was concerned about headroom and efficiency, specially as the speakers were breaking-in and sound was a little uncontrolled. Sonus fabers are also famously difficult to drive and have a tricky impedance curve in the lower registries. Just to see if I was missing anything, I even tried a McIntosh integrated (retail $6K) and a Hegel H-160, both with FAR MORE theoretical and quoted power than the PrimaLuna, and, plain and simply, it wasn't even close. The DiaLogue One blew them all out of the water. No contest. I was in awe. I shared this experience here:
http://www.audioaficionado.org/sonus...lish-room.html
Cut to a few weeks ago. I have been curious about the DiaLogue HP Integrated, which is getting rave reviews, and my dealer was kind enough to loan me one. This one came with EL-34's. I do not have 8 KT-88's to spare, so this was not an apples-to-apples comparison. Keep that in mind. I had all the intentions of buying the HP, and I could get a really good deal on it if I sell my DiaLogue One (they hold their value fairly well), so money was not really a concern here. I REALLY wanted to love the HP.
I will cut to the point: the DiaLogue One is staying. In fact, I preferred it BY FAR. For some reason, the HP was not as open, not as detailed, not as delicate, and not as "ripe" as the DiaLogue One. Amazingly enough, the difference when it came to dynamics and bass grip and control was minimal at best. Yes, it did have SLIGHTLY more control, but at the expense of everything else. The DiaLogue One, I would say, was a 7.9 in that department. The HP was an 8.5. Not worth the trade-off.
Of course, my DiaLogue One is more than broken-in. The HP was not. Also, I'm sure that if I were to use 8 KT-88's things may be different, but I frankly was not convinced that I needed to "upgrade". When I went back to the DiaLogue One, the soundstage was wider, and the midrange was just right. Bass was more than enough. Frankly, I was in shock.
Another thing to keep in mind: more tubes, more problems! More things that can go wrong. More heat (this was evident REALLY quickly in my small room here in South FL, where winter equals 75 degrees at night). More $$$ when it comes time to re-tube (after a few times, you can pretty much buy a new DiaLogue One with the amount it would cost to re-tube an HP with 14 (!) quality tubes).
I did notice one HUGE improvement in the HP, however, and that was the volume control and potentiometer. Dramatically more accurate, precise and smooth when using the remote. I was impressed by that.
But my DiaLogue One is staying. I love that thing more every day. Plus, my OCD tells me that it looks way cooler than the slightly-too-much-of-a-good-thing HP.
Figured I would share this with all of you!