I’m a huge fan of class D amps, although usually on the cheap end of the spectrum.

Recently I purchased a “fosi audio” (brand names seem to rotate) stereo amp with bluetooth. It’s about the size of a raspberry pi.

It is plenty powerful to drive a pair of bookshelf speakers, sounds good, and connects to a turntable and bluetooth source at the same time.

$25 on ebay. Really hard to beat for the price and size