NAD C372 versatility?

I had a 372 as well, though I didn't get around to experimenting with the Pre/amp connection. New they went for under $1000, and I'd say it was decent mid-fi. If you want an improvement, I'd look for a used 375. If you really want to go for separates, Parasound makes some very nice sounding stuff, check out their 2100 or P3 pre amps. Or you could stay in the NAD family with the 165 pre, and an amp from either company would be fine.

These items come up for sale on the used market, but you have to be patient.

I should add that I acquired a brand new C326BEE while I owned the C372. With the C326 I could hear a difference in the approach NAD took when they upgraded from the "2" series, and it was an improvement. Clearer more open sounding than the C372, which sounded a little 2 dimensional and laid back by comparison.

So it would depend on the speakers used, but I preferred the newer NAD line up. The C375BEE would be a solid improvement, they've moved it up market where it now sits at $1499 new vs what the 372 was at, $899. I found an old used ad for a 375 at 950, so not exactly cheap, but I think you'd have to spend considerably more with separates to get beyond the bang for buck level of the current NAD integrateds. YMMV.