EarthQuaker Devices Sunn O))) HalfLife Octave Distortion + Booster

The EarthQuaker Devices Sunn O))) HalfLife is a compact, dual-footswitch effects pedal combining an analogue octave distortion with a clean MOSFET booster in a single pedalboard-friendly enclosure. Developed in collaboration with drone metal legends Sunn O))), the HalfLife is designed to replicate the front-end signal chain used during the recording of the band's Life Metal album, driving vintage valve amplifiers into saturation. It suits guitarists seeking extreme tonal weight, from crushing rodent-style distortion to swelling analogue octave fuzz and transparent boost.

The distortion circuit on the right-hand side — labelled "Amplitude" — is faithfully modelled after the classic White Face distortion unit, featuring a three-way clipping switch that offers OpAmp (no diodes, maximum grinding output), Asymmetric (two silicon diodes and one LED for a valve-like crunch), and Symmetric (stock double silicon diode) configurations. A fully discrete analogue full-wave rectifier provides the octave-up effect, blendable via the Octave control or an expression pedal input for hands-free octave swells. The left-hand "Magnitude" section is a 100% clean, high-impedance discrete MOSFET booster with no added colour, capable of pushing amplifier preamp tubes into harmonic saturation. Signal path runs Octave into Distortion into Boost, with the capability to engage the distortion and boost sections independently.

Because the octave effect is an analogue full-wave rectifier, it is monophonic and performs best on single notes played above the 12th fret using the neck pickup; chords will produce a clanging, chaotic result. The booster does not add distortion of its own but has ample output to drive a valve amp into natural overdrive. Both footswitches feature EarthQuaker Devices' Flexi-Switch® relay-based true bypass technology, supporting both latching and momentary operation. The pedal requires a standard 9V DC centre-negative power supply and should not be run at higher voltages.

Specifications:

Dimensions
5.00 × 2.75 x 2.25 in. (127 × 70 x 57 mm) with knobs

Current Draw
15 mA

Octave Distortion
Input Impedance: 1 MΩ
Output Impedance: <1 kΩ

Booster
Input Impedance: 500 kΩ
Output Impedance: <1 kΩ

Flexi-Switch® Technology
This device features Flexi-Switch® Technology! This relay-based, true bypass switching style allows you to simultaneously use momentary and latching style switching.

• For standard latching operation: tap the footswitch once to activate the effect and then tap again to bypass.
• For momentary operation: hold the footswitch down for as long as you’d like to use the effect. Once you release the switch the effect will be bypassed.

Since the switching is relay based, it requires power to pass signal.

Power
This device takes a standard 9 volt DC power supply with a 2.1mm negative center barrel. We always recommend pedal-specific, transformer-isolated wall-wart power supplies or multiple isolated-output supplies. Pedals will make extra noise if there is ripple or unclean power. Switching-type power supplies, daisy chains and non-pedal specific power supplies do not filter dirty power as well and let through unwanted noise. DO NOT RUN AT HIGHER VOLTAGES!

Artwork by
Stephen O’Malley

Irradiated rat fossil drawing by
Savage Pencil

*Specifications subject to change without notice.