The ZVEX Effects Sylvia Massy Woolly Mammoth is a fuzz pedal built for both bass and guitar. ZVEX describes it as "a monstrous fuzz pedal that delivers crushing low end for bassists while also blistering on guitar"1. It is a special edition of the Woolly Mammoth design, made in collaboration with Sylvia Massy, and it sits alongside the other Woolly Mammoth versions in ZVEX's fuzz range, such as the Zvex Woolly Mammoth and the ZVEX Woolly Mammoth 7.
Who designed it
The pedal carries the name of Sylvia Massy, whom ZVEX introduces as a "legendary record producer and artist (Tool, System of a Down, Prince, Queens of the Stone Age, and more)"1. It is a signature edition: Massy also created the artwork that appears on the enclosure, which ZVEX applies as a UV print1.
A limited run of 60
This is a limited edition pedal. ZVEX offered 60 units, "each hand-assembled and hand-numbered"1. The artwork is described by the maker as "Stunning UV-printed artwork by Sylvia Massy"1.
Transistors and circuit
The Sylvia Massy Woolly Mammoth uses "Hand-selected & tested NOS 2N2222A transistors for unrivaled tone," according to ZVEX1. NOS stands for new old stock: transistors manufactured in an earlier period and kept unused, which players of silicon fuzz circuits often seek out for their character. The 2N2222A is a silicon transistor, the same general family used in other ZVEX silicon fuzz designs such as the ZVEX Silicon Fuzz Factory.
On bass and guitar
The Woolly Mammoth design has always had a foot in both worlds, and this edition is pitched the same way. ZVEX's own description puts the low end first, saying the pedal "delivers crushing low end for bassists while also blistering on guitar"1. For players looking at fuzz for bass specifically, the site also keeps a broader listing under Bass Pedals, and the Fuzz Pedals page gathers the wider category.
Videos
bassfuzzcom
The Bass Channel
The Tone King
Questions
Who designed the ZVEX Sylvia Massy Woolly Mammoth?
The pedal was designed with Sylvia Massy, described by ZVEX Effects as a legendary record producer and artist whose credits include Tool, System of a Down, Prince, and Queens of the Stone Age. It is a special edition of ZVEX's Woolly Mammoth fuzz, carrying her name and her artwork on the enclosure.
How many Sylvia Massy Woolly Mammoth pedals were made?
ZVEX Effects offered 60 units of the Sylvia Massy Woolly Mammoth. Each one was hand-assembled and hand-numbered, and the enclosure carries UV-printed artwork by Sylvia Massy herself.
What transistors does the Sylvia Massy Woolly Mammoth use?
The pedal uses hand-selected and tested NOS (new old stock) 2N2222A transistors, which ZVEX describes as delivering unrivaled tone. NOS means the transistors were made in an earlier era and kept unused until now.
Can you use the Woolly Mammoth on bass?
Yes. ZVEX describes the Sylvia Massy Woolly Mammoth as a monstrous fuzz pedal that delivers crushing low end for bassists while also blistering on guitar, so it is built to work on both instruments.
Sources (1)
- Sylvia Massy Woolly Mammoth, ZVEX Effects








