I think your amp and speakers are pretty solid, so I highly suggest getting a Bluesound Node2i and get a Qobuz subscription that’s on special right now for $15/month and is a much better deal than hi-res Tidal IMO. The Node will solve several of your issues as you can ditch the computer while still being able to play your stored music, and the DAC in the Node is pretty decent and may well be an upgrade from your Zdac. Between significantly upgrading your source material, getting rid of the noisy computer, and quite possibly getting a better DAC you should realize a rather significant jump in sound quality and overall enjoyment I’d think. Hope this helps, and best of luck.