Nemphasis breathes new life into bass preamps with O2 Oxygen pedals

Officially announced at NAMM and now available to buy, Nemphasis's new O2 Oxygen bass preamp pedals promise to fulfil pro bassist's requirements on stage and in the studio.

The larger Pro Series O2 packs a three-band EQ section with mode footswitch, which lifts the pedal's EQ and volume for solos and highlighting noteworthy runs.

Elsewhere, a gain control and input level cater for passive and active basses, while a ground lift switch gets rid of an earth loops - an XLR output delivers a balanced DI out, too.

The regular O2 offers the same functionality as its bigger brother, but does away with the DI out and switchable modes while adding a toggle switch for preset mid boost or cut; in addition, an internal bass boost adjustment offers extra low-end.

The Pro Series O2 Oxygen Bass Preamp and O2 Oxygen Bass Preamp can be powered by standard 9V power supplies and are available now for £189 and £149 respectively.

Michael Astley-Brown

Mike is Editor-in-Chief of, in addition to being an offset fiend and recovering pedal addict. He has a master's degree in journalism, and has spent the past decade writing and editing for guitar publications including MusicRadar, Total Guitar and Guitarist, as well as a decade-and-a-half performing in bands of variable genre (and quality). In his free time, you'll find him making progressive instrumental rock under the nom de plume Maebe.