Which is better for sound, assuming one or the other must be 4 metres and both are quality cables, USB cable between dac & computer or audio cable between dac and amp?

I have been an avid music consumer for decades - vinyl on a super system - but I now live on a narrowboat with limited space and power so I'm trying to put together that perfect system again in my new environment. I have a Temple Bantam Gold 12 volt T-amp driving a pair of Klipsch speakers and...