Hello, I'm the OP. Thank you to those who left kind words re my original review, I appreciate your feedback. And thanks for those of you who added to the debate, particularly those who left your own thoughts and opinions on the amps.
Below I post some answers to questions posed along the way.
What happened next?
DUCKWORP, I would be interested, after your exhaustive comparisons, in what you decided to do in your quest for a change of system.
Mike, I had decided that the Vitus RI-100 was the amp I wanted. My Vitus dealer is Richard from Lotus hifi. Richard is an all-round good guy and a very knowledgeable and helpful dealer. I asked him, before I pressed the button, if I could hear the next amp up in the Vitus range: an integrated Class A amp called the SIA-025. He did actually and genuinely warn me not to as he said I would find it hard not to resist it! Oh dear, true words. Anyway, Richard brought it over, set it up, and we had a listen from cold. He left the RI-100 with me to compare the two. To be perfectly honest, on that first listen I couldn’t actually detect a difference between the RI-100 and the SIA-025. But Richard said to leave it running for some time and have a listen later. So I left it overnight and came back to it 24 hours later. Wow! First thing I played was Solid Air by John Martyn, a fave reference track for me with its double bass, plucked guitar, and sumptuous vocal performance. I was left open-mouthed. The pure silkiness of the sound was extraordinary, just drop-dead gorgeous. It was smooth without being smothered, it maintained all the detail and clarity of the RI-100 but produced this wonderful sound with huge depth and subtlety. I switched back to the RI-100 to check I wasn’t imagining this, and to the Naim set-up. I was not imagining it. I tried different types of music which revealed that the differences were really noticeable on acoustic, jazz, classical, and vocal music: on these the music had more depth, more openness, and this feeling that I cannot describe other than a silkiness I had never heard before. Not the velvety warmth of the Luxman, but a very natural smoothness. On rock and electronic the differences to the RI-100 in my system were less evident except in the bass department where the SIA-025 had a more natural bass.
So after hearing the SIA-025 I could not resist and pressed the button. It was more than my original budget, but hey, who hasn’t done that before? And now I have my forever amp, no more upgrading necessary. And by the time I had factored in the NAIM 552 trade-in value the SIA-025 was in line with what a NAP300 plus new rack would have cost (just listen to that justification self-talk!). The sound difference, for my taste, is so huge.
However, the reason I didn’t review the SIA-025 in the original post was that the point of the original review was to look at amps which cost the same as the trade-in value of the NAC 552 (£10k), and I had the other amps in my system simultaneously with the RI-100 and Naim, so I felt that the review would be better to concentrate on the RI-100.
How I referenced the amps vs each other
B.t.w., how did you acquire the review kit, apart from your Naim, that is, and did you review different amp's at different times, using notes but referencing the other three against the Naim on separate occasions?
Good question. The Naim and the RI-100 were common throughout the whole process. The Luxman came in and out, followed by the Devialet. So I could make easy a/b/c comparisons between the Naim/Vitus/Luxman and then the Naim/Vitus/Devialet. I did not make listening notes but I have a good aural memory!
The dealers I used
how did you acquire the review kit, apart from your Naim, that is?
As I say above the Vitus was from Richard at Lotus hifi. Richard is great - he knows his stuff inside out and offers a real first class service to his clients. I thoroughly recommend him.
The Luxman and Devialet came from another fantastic dealer: Saj at AudioVenue in London. Saj always offers advice that is right on-the-nose, and runs a superb hifi business in West London.
The Naim/B&W and Vitus/B&W combo
I’ve certainly not ever come across recommendations for Naim amps mated to B&W speakers. Only heard that combination once; it was sharp and nasty.
I chose the B&Ws back in 2012 when I demoes a bunch of different speakers at the Grahams store in London. I cannot recall all the speakers I tried but one was Spendor, and another was a Naim speaker. The B&Ws were far and away the best even though they were beyond my intended budget. In my system they were never sharp & nasty. They were far more open than my previous Linn Ceilidh speakers, but I would get Naim listening-fatigue from both the old Linns and the B&Ws.
With the Vitus the B&Ws sound amazing though I know I can get more out of the Vitus. I have demoed various other speakers but found that all of them have a bass boom in my room which is unpleasant on much music recorded post 2000. The frequency my room resonates at seems to be underrepresented in the bass output of the B&W 804D so for now they remain in my system.
SAM on the Devialet
As a matter of interest was the Devialet tried with SAM turned off? O
The SAM was set up by the dealer Tony, who knew the speakers I had. I did not change it and so I am guessing it was on but I cannot answer for sure.
Room acoustics
Great write up but why dont you fix your room acoustic problem before changing amps etc?
Thank you for your complement Rodney. With respect to the room: it is a cuboid room with a bay and an acoustic engineering friend tells me the problems are from a cuboid room which is notorious for boomy bass, along with odd reflections from the bay window. I could solve this by using triangular bass dampeners/absorbers along the ceiling/wall join. Unfortunately my listening room is also the lounge/tv room/family chilling room and the ‘look’ would not be acceptable. If I fire the speakers down the room from the bay the boom goes away. But unfortunately this also won’t work given the other uses of the room. Real life gets in the way again!
Teddy & Naim
Perhaps try the Teddy integrated or pre/power options and compare them with your Naim NAC 552 / NAP 300 as the description of the Vitus RI-100 is quite similar to the Teddy gear.
I really enjoyed reading your comments Ryder, your descriptions of some of the sound I was trying to describe were articulated better than I could do. With regard to Teddy, I use Teddy Power Supplies on my second system (a Naim CDX and 282) and think that they are exceptionally good value for money. I never did try Teddy's amps though, they were not easy to demo without ordering from Teddy and then returning, which always seems a lot of effort and cost given the import duties which would arise.