Paul is famously mum about his tone, but since the release of Schadenfreude there have been some hints around the internet.
The first element is his #1 bass. It is an 80’s Fender Precision Bass Elite II, almost identical to this but now worse for wear:
Fender Precision Bass Elite II In the Life as a Mannequin video, the headstock is painted black, indicating that it has been replaced. But the double P pickup configuration of this active bass lends itself to that huge, round sound.
Here is a recent pic of Paul and said bass:
I cannot dig up the references, but I recently stumbled on Josh Newton talking some poopie about gear and dropped a goof on Paul about his Peavey 400. This makes so much sense because Paul is a pawn shop urchin and pawns were lousy with these in the 90's. But more importantly, they have brutal distortion and fuzz built in. Once I heard this it all made sense. This demo gives you an idea of what is possible with this clunker:
Finally, let's consider the "symphonic" quality of his tone (I have heard this description many times). There is this wonderful doubling chorus-like sound to his tone. Paul being an engineer I figured he did a lot of double tracking, but suspected something else was at play. Well the latest Third Gear Scratch podcast settles this for me. Although Allen Epley wouldn't let Paul give up the tuning, they both discussed the secret sauce: a unison tuning.
Episode 46 - Paul Malinowski — Third Gear Scratch — Overcast
Based on Paul's initial statement before being cut off by Allen, Paul lets fly with "G and C", and Allen says "not fourths" leading me to believe the tuning is CGGD, with the unison tuning int the middle! If you watch any live footage, you will notice two things: Paul wraps his thumb around to fret the C, but also plays a bar across the middle strings with his middle finger. A lot. You can see all this oddness in this performance of Cake: