Basically, the title.
if you mean something like replaygain so that quiet tracks are the same loudness as loud tracks then no… at least there wasn’t anything back when i was looking into this last year.
what i found was rsgain which allowed me to process my library from the command line and apply meta data that certain audio players would make use of and adjust the volume between songs.
music packages like gmusicbrowser will also process your library but they are slow so i mainly use it only for editing the meta data.
i settled on clementine for playback because it used the replaygain data (if you turn that feature on in the settings).
but last time i tried this under 24.10 there were issues with playback and audio glitches there were not present in other players, so i think it may be related to the replaygain processing and the switch to from pulse audio to pipewire
TLDR No
Youtube always has replaygain enabled (annoying), but stable volume is an effect chain, the important part of it is a compressor/expander. To my knowledge, Google haven’t published any details of exactly what it is.
There’s nothing like this in plasma. You can do this very nicely in linux with pipewire filter chains, wireplumber smart filters, and ladspa plugins. That’s kinda nerdy to set up, though.
There’s one limitation at present: Linux has no surround compressors. If you want mono or stereo it will work well.