Here are the listings of some of the pretty cool guitars used by Jason for his cruel and mindboggling guitaring.

Normally used one's:

Sadowsky E-Bass Guitars
Sadowsky - Lake Placid Blue Vintage
Sadowsky - Black Vintage - Ash body
Sadowsky - PJ - Cherry Sunburst
Sadowsky - PJ - Caramel Sunburst
Sadowsky - Vintage - Black (x2)
Sadowsky - Vintage - Cherry Sunburst
Sadowsky - Black Vintage - 24 Fret (x2)

Other Bass Guitars:

1958 Fender Prescision
1981 Spector NS (4 strings)
Zon fretless
1963 Gibson EB-3
Gibson EB-6 (6 strings)
1968 Fender Telecaster Paisley Bass
Chandler Metro Baritone
1933 National Dobro
Parker Fly guitar
Hagstrom 8 string
Music Man (4 strings)
Music Man (5 strings)
Stuart Spector Designs 4 - 5 - 6 strings
Hamer 8 string
Hamer 12 string

Rumored Bass Guitar:

Gene Simmons' Axe Bass

Amplifier:

Mesa/Boogie 1x15 combo
Ampeg SVT cabinets
1974 Ampeg SVT head
Mesa/Boogie with SWR Heads
Gibson Skylark Guitar amp
Fender Folded Horn 1x18
Ampeg SVT III
Ampeg SVT Vintage
Ampeg SVT 8"x10" Cabinets
Ampeg ISO Vent 10"x15" Cabinets

Effects:

Boss Flanger
MXR Phase 100
Mu-Tron
Korg G-5 Bass Synth Processor
Electro Harmonix Big Muff
Alesis Mediverb II
BBE Sonic Masimizer
Morley Power Wah Boost

Strings:

La Bella strings

Picks:

Dunlop Tortex Blue Triangle