Currently I use SoundConverter (https://soundconverter.org/) to convert FLAC to Opus files. It works very well for my purposes, but wanted to know if I’m missing out on something that another tool does.
All my music sounds fine, though a lot of older tracks sound flat. I attribute it to quality loss at every step: these were imported vinyl, mixed and released on CD in the early 90s. Some of them just don’t have much data.
Anyhow, if you have a recommendation, let me know.