For anyone who is interested, I was able to spend some quality time with the new Diavolo this weekend. I had a friend and fellow audiophile over, and we A/Bd the Primaluna with the Diavolo, playing the same suite of songs (some vinyl, some SACD) through the Primalune, the Diavolo with it's stock KR Audio VV32B tubes, and also through the Diavolo with a pair of Emission Labs 300B-XLS tubes.
Overall, this incredibly fun and interesting science/audio experiment/shootout confirmed that the Primaluna amp, particularly with the NOS tubes I was running, is a great amp. And if I were 15 years younger and in the habit of hosting large parties where I would be playing hard rock/heavy metal music at ear bleeding levels, I would keep the Primaluna. But alas, the Primaluna is, as of this morning, for sale on this site.
In short, the Diavolo doesn't "trounce" or "blow away" the Primaluna, but there are noticeable differences, particularly with the 300B-XLS tubes. It would have been a closer call with the stock VV32B tubes. The Diavolo with the 32B tubes had, hands down, the best bass I've ever heard in my system. Tight, full and punchy, just unreal in the bass department. The midrange and treble was very detailed and very nice, but not noticeably better than the Primaluna from the middle up, in sound, imaging or soundstage.
Then we put the 300B-XLS tubes into the Diavolo and listened to all the same songs...
The difference was immediately noticeable and quite striking. I kept hearing myself say "I've never heard that song sound that good." There was definitely a loss in the bass department, but it's one of those things that you don't miss if you don't have it, you just enjoy it if you do have it. And the midrange and treble were silky smooth, detailed, rich and full, and in particular voices and cymbals were more real than anything I had ever heard. I don't know if the Diavolo is truly "neutral," but honestly I think my system was incredibly neutral and revealing to a fault before I got the Diavolo, and the Diavolo with the 300B-XLS tubes warmed and smoothed things to a point where it's just beautiful music that makes me want to listen to more and more of it.
One shortcoming is that with heavier tracks (Led Zeppelin and Rush for example), my system still sounded great with the Diavolo, but when I cranked it up to super loud levels there was noticeable distortion and I had to turn it back down. According to my SPL I could get it to about 90-92 DB without distortion, which frankly for me is plenty, but I have a small room and I can see that the limitation could be an issue for some people particularly in larger rooms.
Tonight I listened only to the Diavolo with the 300B-XLS tubes without any switching or A/Bing, and had to drag myself away after a few hours because I was enjoying it so much.
I think the Diavolo is a world class amp which makes my system sound better than it ever has before. The difference between it and the Primaluna with the NOS tubes is not dramatic, but it is signiricant, particuarly with the 300B-XLS tubes. I look forward to listening to more of my music collection through my system.
Maybe I can be done upgrading/tweaking for a while now? :)
