I'm hearing that clip above... There's NO way that's a stock cranked Superbass or Superlead. Listen closely at :35 and you can hear a sudden hiss when he goes to his monitor. There has to be a dirt pedal being used.
I'm starting to think it's modded. The Hairy Brown Eye mod that @NewReligion did on my 2203x sounds VERY similar to Adam's core tone... that leads me to believe that Dave Friedman (who services Adam's Marshalls) is lying about "returning it to stock Superlead specs" and actually modded the thing for high gain.