opinions on best neutral sounding amp with DAC under $4K

I don't know if this would bother you or not. The Hegel 160 is made in China.

When I first saw your post title, the piece that immediately came to mind was the Hegel H160. Since you're already thinking about that one, you're on the right track. An excellent integrated with a pile of awards. Disclosure: we are a Hegel dealer

All my Apple devices are built and China and they perform superbly! So it doesn’t bother me, it is the quality no origin of manufacture.

I borrowed the 160 from my local dealer for a few days.  Sadly I was unimpressed.  Tried a few different power cords etc., and could not get it to sound good.   Decidedly mid-fi in my view despite the 'professional' reviews.

I say sadly, because the choices at that price point are very limited.  Just recently sold the Naim v1/nap 100 combo - about the same price.  Again not impressed.  Have finally settled on a McIntosh D150 digital pre, which is excellent.  Pick a power amp to suit your tastes.