I think the comments that generalize about tube amps and HF rolloff (and "too buttery", etc.) is a criticism that some amps and preamps have earned. But that is simply not the case with higher-end tube components in today’s world.
What am I missing? The liquid smooth midrange, buttery treble of the Luxman, which was the main reason I went from Class-D to it in the first place.
@erik_squires The differences we hear between amps is the distortion signature of the amp. You’d think vanishingly low distortion would have got rid of that issue, but since our ears are highly attuned to higher ordered harmonics that vanishingly low distortion really isn’t as low as it needs to be. Just like they do with musical instruments, our ears assign tonality to harmonics and so higher orders add brightness and harshness.
Many tube amps don’t have the higher orders as audible since they are masked by lower orders. That is why the sound smooth and not as much high frequency energy; its nothing to do with bandwidth, which tube amps have had for many decades. The HK Citation 2 easily makes 50KHz so its not a bandwidth thing. That is why I included the first quote above.
Once you understand that its distortion that causes amps to sound different then as a designer you have an access to getting the amp to sound musical and correct. It helps to know how to apply that understanding to the technology.
The bottom line is there are class D amps out there that are nice and smooth and don’t take a back seat to the Luxman. You just have to seek them out.
Like you all need me to participate to begin with.