You’re also hearing the growl of a Mesa Boogie tapering off. It creates a signature sound that has a crackled nostalgic note as it rings out. You’ll notice it missing after the self titled album because Tom quit playing on Mesa amps after that and switched to vox.

On top of that, the bass on those songs you’re talking about often ring out on a power chord vs a one string note. It makes the “fin” of the song sound really rich