Sources: Michell GyroDec turntable, Aqua Formula DAC driven by a Mac Mini, Roon integrated with Tidal and Qobuz, Accuphase DP-65V CD Player, Accuphase T-1000 FM tuner.
Very nice job. I love the idea of implementing old school audio with new school computer technology. Couple of ideas for you, try importing your music in Apple Lossless format. This will be a much better than the AAC files you have. There is also a great applescript called Lossless To AAC Workflow, it will take a cd, import Lossless to your computer, and then convert to AAC, add the AAC files to your ipod, and then delete the AAC files from your computer so you don't have duplicates (It works great)!! From there you could look into a high end DAC because you have optical out on the G5. I have found this to work great because the computer is strickly a transport, and has very little effect on sonic quality. Happy listening!!