unpopular amp I guess
I have had my NAD298 running in tandem with an NAD 275BEE for about two years now. The 298 feeds a pair of Martin Logan Motion 40's while the 275 feeds two Martin Logan 35XTi's. Front end preamp is a Rogue RP-1.
My experience is that the A/B Class AMP 275 is more expressive and matches up better with the 35XTi's because the Folded Motion XT tweeter is bigger on the bookshelf sized 35Xti's than the Motion 40 towers. For a time period, I had the D-Class 298 hooked up to the 35Xti's, but the amp overwhelmed the bookshelf speakers with power - just as one would suspect judging from specifications alone.
What I get out of this setup is plenty of power with great bass (no subs) with virtually no heat. (The 275BEE gets slightly warm at best).
A simple search of "NAD" (on Agon) results in 19K+ responses, while "Yamaha" nets only 12K+ responses.
That, in and of itself, suggests that NAD is a more popular topic and brand than Yamaha.
@goodlistening64, curious why you need to bridge to 500watts? ML Motion 40 are not hard to drive unless you're having a back yard BBQ club party and need 1000watts. Are you looking to push the amp to max wattage?
I am merely running two amps in order to power two sets of speakers. The Motion 40's can handle 300 Watts and the C298 offers up 340 Watts at 4 ohms. The 35Xti's spec 250 Watts with the 375BEE maxing out at 250 Watts. My preamp, the Rogue RP-1, has 60 steps in 1 db increments and we typically listen to music around 30 db, so I figure the output is about 50% per amp.
Hence, the 40's typically are getting about 170 Watts while the 35's receive about 125 Watts. Both amps have gain settings, so one speaker is not louder than the other, but the 35Xti/375BEE certainly does add "sparkle" which the 40/C298 duo cannot match. So each speaker is getting just the right amount of power during play in order for them to sound their best..it is a fair amount of power without the creation of any discernable heat.
In the past if you ran 295 Watts of power for 3 hours the heat would be unbearable. While the D-class amp does not have the refined sound as the A/B amp, it serves the purpose of doing what the 35Xti's cannot do: create solid bass waves while filling up the lower midrange frequencies.
It is worthy to note that when listening to music - even with the amps running 50% of power - we can have conversations in normal voice tones, even across the room. What I have learned - and took some time to figure out - is that good interconnects and cables, a better set of output tubes - as well as room dampening - give the sound a tonal quality that takes the edge off the music that motivates one to "turn it down". As time goes by, the music has settled quite a bit and I expect that the volume will go up a few more db in the future because of the "settling in" factor. It is real and generally follows a "bloom".
Not for the faint of heart, this journey has taken a good 10 years and probably close to 15K in funds. My wife was resistant, but has since come around and now provides me with a daily set list.