"I tried a friends Bel Canto Ref1000m's with a power rating of 500w at 8ohm and 1kw at 4 ohm , they produced much lower volume levels than my 200w at 8 ohm A/B designed Levinson amp ."
Was volume level determined just by listening?
Try it again with a sound level meter and see what that says.
I thought the same of the BC ref100ms when I first heard them in contrast to teh more conventional 120w/ch Musical Fidelity A3CR I had prior. It was totally disorienting compared to what I hard prior in taht the sound is totally different, more dimensional and fewer loudness cues it seems, more like how a well designed tube amp would go loud than any Class A/B amps I could compare with.
Also, damping factor is very high and the control and detail was and remains absolute and vice like with my fairly large, power and current hungry OHM 5s, which these were acquired specifically for again once you get used the expanded and radically different 3-dimensional soundstage presented that this occurs within.
I suspect Class D amps have lower current delivery requirements to produce results similar to higher current class A or Class A/B amps due to their switching nature that is the basis of their efficiency in comparison to Class A/B. ANother benefit of this in addition to efficient usageof availble power is the amazingly small size possible with Class D switching technology compared to other less efficient designs.
In regards to sound quality alone (as opposed to energy efficiency and associated total cost of ownership), I probably would not recommend the BC or similar Icepower amps as strongly for speakers that do not benefit from high damping factors like the OHM Walshes do.
FWIW the BCs do work very well with my small Dynaudio Contour 1.3mkII monitors as well, although these are also known I think to like power, current and damping though to a lesser degree than my large OHM Walshes.
A funny story on this topic. The other morn, I had the big OHMS cranking off the BC amps in my larger basement listening room with the sliding glass door behind them paritally open. I was listening in teh room comfortably with no signs of sonic stress or fatigue. MY wife came down and reported that she could hear the music over a block away and from the direction opposite the open door when she was returning from walking the dog ( I had to mute the sound to be able to hear her talk next to me however). I don't think I would have ever been able to handle the volumes I like to listen at when the music calls for it these days for long with any of my prior amps that were also capable of going quite loud. The BCs go as loud as I suspect most anyone would ever need with most any speakers in most any room and have yet to EVER show any indications of breaking a sweat. Most impressive, especially when you soak in how tiny those boxes are!
