I thought that last part would necessitate processing through the amps DAC as the final step before stereo output.
It has nothing to to with turntable and analog signal.
If you're listening to digital source then you need a DAC.
For analog source you don't need a DAC at all (it's nonsense).
You need DAC only if you want to convert your records to a digital files for use on your computer or media player.
The amp must be matched to the speakers, there are low power amps and high power amps. There are also low efficient speaker and high efficient speakers. A low power amp designed for high efficient speakers only.
Everything will affect the sound, even your room size.