Just an update since the last post. First is that I acquired a Primaluna Dialog Premium tube pre-amp. I was not prepared for the changes to the sound once I plugged it into my stereo. Up until then I'd used my 1976 Kenwood KR-9600 Receiver (fully recapped) which I thought sounded quite good.
This was a whole different beast: soundstage was bigger, all instruments and vocals took on a more natural sound, but what was even more surprising was detail improved. Cymbal work on a Jazz CD I have was so much more prominent it's like it had been dirty before.
The next addition was a set of Dunlavy Cantata speakers. Up to then I'd been using a pair of 1978 Genesis Physics Model III speakers that sounded quite amazing; detailed, great 3D image, and nice deep bass. The difference with the Cantata is an even better image, more detail and very deep, tight bass.
These new additions are run with the pair of NAD 2200 amps in mono. Both these amps are original, not modified or updated.
After these 2 purchases I had a chance to evaluate 3 different stereo power amps: Musical Fidelity A3CR amp, Simaudio MOON 300A and a VTV Purifi VTV Purifi Eigentakt EVAL-1. The first 2 were no contest; in contrast to the 2200s they were thin sounding, in fact the same music that sounded so good with the 2200s just sounded uninteresting now. I played the 300A for a full day, I couldn't enjoy any of the music I know well, everything sounded clinical.
The big surprise was the VTV. I will note that it accepts XLR only, and I had a pair of plug in adapters into the VTV so I could use RCA. This I'm sure affected the overall performance. So working with what I had the VTV also sounded thin, weak, clinical and uninteresting.
With all 3 of the stereo amps I had to crank the volume up higher. Where I can keep it at 9pm with the 2200s, the others I was up near 10pm and it still couldn't match the sound levels.
Each time, switching back to the 2200s, the music is just amazing. No matter what music is playing with any medium everything sounds great. I was a bit concerned when I realized going from my Gen III speakers (8 ohm) to the Cantata (4 ohm) with the 2200 in mono could be an issue. But then I read this:
Bridging The NAD 2200 is so powerful in the normal stereo mode that few listeners will ever need more. For special situations the two channels of the 2200 can be bridged to form a mono amp of truly immense power. Its rated continuous sine-wave output is 400 watts, while its dynamic power output exceeds 1200 watts into 8 ohms and 1600 watts into 4 ohms. Two 2200s in bridged mode (delivering over 3 kilowatts into a pair of 4-ohm speakers) would cost about the same as an ordinary 400-watt amplifier.
And therein lies another issue (if you can call it that): to get another amplifier that can compete with the 2200s mono level of performance I'm seeing costs many times higher to match them. Add to that their enjoyable musicality with all mediums.
It's easy to see specs on the websites for amps, but until you actually hook them up to your system in your room and hear them, they could sound either fantastic or surprise you with having little synergy. With the setup I have now everything works, and maybe I just got really lucky that the synergy is there.