I am considering using Roon.
I have a Macbook Pro, an iPad, an iPhone, and a pair of Kef LS50 wireless.
I have read in your Roon database that “With the arrival of 6TB and 8TB drives, most people no longer need a multi-disk NAS in the home because all their music can be stored on a single drive, and less expensive machines for running your audio system exist.”
So, instead of NAS, and without using a computer, what would be the “less expensive machines” that you talked about ?
If you have no prior experience with Roon you could run a trial from your Macbook before investing in dedicated hardware.
You haven’t listed a NAS so I assume you don’t have one right now. In this case a supported Intel NUC with an USB attached disk (SSD or HDD) would be a good choice. More here:
By far the easiest way is connecting drives by USB to the machine hosting your core. However they will be full sized 3.5 inch drives so you’ll need a self powered caddy or a products like the IcyBox JBOD USB enclosures. The smaller and neater 2.5 drives have smaller capacities but can be powered direct from USB.
I have 2 24tb nas devices (one at home and one at the boat and they mirror each other). I now only use the nas to backup my music and travel with the nuc and an external 4tb wd drive. When I update my music i copy it to the nas(s) as a backup. Now when I mark something as a favorite for instance it comes with me instead of having 3 different lists. It was a reasonable simplification and improvement in sound quality and convenience.