Sheehan uses his Yamaha Billy Sheehan Attitude bass on tour. He's currently using the third version, which has a specially-designed new neck pickup. Each pickup has its own output and separate Line 6 wireless units. The bass also has a deep neck joint that attaches at an angle. The guitar's body is made of artificially aged wood. As with all of Sheehan's basses, it has a Hipshot D Tuner. He uses a custom set of Rotosound strings gauges 43 - 110.
Sheehan uses a Pearce BC1 preamp, though he says he only has three left before "that's the end of it." He uses it for distortion and clean. He uses the Ashly Audio compression unit on the clean side of the Pearce, as well as on the Hartke LH1000 for his low end. In addition, he uses the ISP Decimator ProRack.
The signal comes out of the Pearce preamp and splits via the neck or bridge pickup into a LH1000 for low end and an LH1000 for pedals, as well as an HA5500 for his high end.
This pedalboard is basically similar to Taurus pedals in a different format that trigger a Roland SonicCell.