Sounds to me like the Krell would fit the bill for the attributes you are seeking.

However I also disagree with Dave regarding Accuphase/Luxman amplifiers.

For one thing the current Luxman amplifiers are a whole different kettle of fish to the Accuphase models.

The Accuphase range majors, IMO, on natural sound albeit lacking that hi-fi punch that so many seem to crave. To my ears they do exhibit a slight bass tubbiness which may line up with Steve's observation. This doesn't detract from the lovely midband and natural treble.

The Luxmans, I speak here of the class A jobbies, are slightly more vivid than the Accuphase equivalents with a tighter bass. Still with that open midband and natural treble. They are also way more powerful than the specs would lead you to believe, although as they go beyond the Class A cited spec I believe they drift into Class A/B.

One thing they do both offer is useable tone controls, shock horror

The Krell sound to me is more immediately impressive but, for me, over the long term that trick soon wears off.

Incidentally I don't think the smaller integrateds are specced to deal with difficult loads as well as the behemoths further up the range.

I have owned Krell in the past and currently have a Luxman L-550 AII.

I do agree with Dave in that the Krell 400 is much less clinical than the 300, looks nicer too.

I guess it depends what you are looking for and the best way is to try before you buy.

As always YMMV