Need an integrated amp that sounds engaging at lower volume

May I please have any recommendations for an integrated streaming amp to match with Sonus Faber bookshelf speakers? My best friend wants help picking out a stereo, he's no audiophile, but he loves and collects music and he can afford a decent stereo. He wants the Sonus Fabers, so the speakers are fairly settled.

I don't stream music much but that's all he does. I have a Hegel H200 which I love but my concern is that this amp seems kind of laid back at low volume, and this guy listens to music at fairly low volume, otherwise I'd recommend a Hegel H360/390.

So I'm thinking something with a little kick and nice midrange at lower volumes would be perfect, but I would appreciate suggestions very much b/c I never had bookshelves and I like music fairly loud. If there's an amp that fits the bill under $4,000 all the better.

Thanks!