Jeroen proudly endorses WARWICK basses and plays Thumb NT series exclusively since 1993. He has played several Thumb NT6 and NT7 basses, each marking different chapters of his musical career. During PESTILENCE's 'SPHERES' era he started playing Thumb NT 6-string basses. From 2005 and later on recording OBSCURA's second and third full-length albums 'COSMOGENESIS' (2009) and 'OMNIVIUM' (2011) he played fretless Thumb NT 6-string basses. Since 2011 he plays fretless Thumb NT 7-string basses, masterbuilt by WARWICK's custom shop in Markneukirchen, Germany.

• Warwick Thumb NT 7-string fretless Ebony fingerboard (2017)

• Warwick Thumb NT 7-string fretless Snakewood fingerboard (2013)

• Warwick Thumb NT 7-string fretless Ebony fingerboard (2011)

• Warwick Thumb NT 6-string fretless Macassar Ebony fingerboard (1993)

• Warwick Thumb NT 6-string fretless Ebony fingerboard (1991)

• Warwick Thumb NT 6-string Wenge fretboard (1991)

• Warwick Thumb NT 6-string fretless Asian Ebony fingerboard (1989)

• Warwick Thumb NT 6-string Wenge fretboard (1989)

Tuning: F#(0); B(0); E(1); A(1); D(2); G(2); C(3); Strings: Warwick Black Label - medium stainless steel round wound; String gauges: .175; .135; .105; .085; .065; .045; .025; Pickups: Bartolini 7-string P4 soapbar XXP47C; Electronics: Bartolini NTMB, Bartolini EZQ; Outboard gear: Phoenix Audio DRS-Q4 MKII dual channel preamps; Kush Audio Electra - dual channel electrified transient equalizer.