The iconic hammer-on intro is played clean-to-crunch on a cranked Marshall. Bridge pickup, no pedals.
Signal Chain
Marshall Super Lead 100W→4x12 Greenback→Output
AmpMarshall Super Lead 100W
bass
4
gain
8
mids
7
treble
8
presence
7
Cab / IR4x12 Greenback
micSM57
mic positionoff-axis
Notes
The hammer-on intro needs clean technique at low speed first. SG bridge pickup is key for the bite.