I run a second Unraid server with a couple of backup-related applications, as well as Duplicati. I have my main server network mounted and run scheduled jobs to both copy data from the main pool to the backup pool, as well as to Backblaze. Nice having the on-site backup as well as the cloud based.
I occasionally burn to 100gb blurays as well for the physical backup.
It sucks but a cheap USB sound blaster would work fine here…