@yth Oh, SID. I've been listening to music by Linus Åkesson, who uses SID a lot. His music is generally better than most of the chiptune I've listened to, though it still hurts my ears sometimes.
https://open.spotify.com/artist/5pNzJPIgMhTzSq6kxpFaGc
Some of his albums say something like "RESYNTHESIZED"-"with alias-free oscillators", so maybe he played the music data through something without the soothing filter you're speaking of?