Earthquaker Devices Sunn O))) Half Life Octave Distortion plus Booster

Earthquaker Devices’ Sunn O))) Half Life pairs a three–mode octave distortion circuit with a dedicated booster in a compact stompbox. Designed in collaboration with Sunn O))) and featuring artwork by Stephen O’Malley, this pedal delivers the low–end saturation and grinding tone synonymous with drone and experimental music. Three clipping modes—OpAmp, Asymm, and Symm—give you everything from unfiltered digital aggression to smooth, valve–like compression, all switchable on the fly.

The distortion section runs no diodes in OpAmp mode for maximum assault at high volumes, while Asymm mode uses two silicon diodes and one LED for a slightly compressed crunch. Symm delivers the classic double silicon diode tone. Both circuits run 1 MΩ input impedance and sub–1 kΩ output impedance. The booster section (500 kΩ input, sub–1 kΩ output) stacks in front or independently for level shaping. Flexi–Switch® Technology allows momentary or latching operation from a single footswitch. The unit measures 127 × 70 × 57 mm, draws 15 mA, and requires a standard 9V DC supply with 2.1 mm negative centre barrel.

Relay–based switching means the pedal demands clean, isolated power to pass signal without noise. Avoid daisy chains and switching–type supplies; use a dedicated transformer–isolated wall–wart for best results. The dual–circuit architecture lets bedroom producers and live engineers dial in everything from subtle low–end colour to apocalyptic saturation without leaving the pedalboard.

Features

• Three clipping modes: OpAmp, Asymm (LED), and Symm silicon diode
• Dedicated booster circuit with independent level control
• Flexi–Switch® momentary and latching footswitch operation
• Input impedance 1 MΩ distortion, 500 kΩ booster
• Output impedance less than 1 kΩ both circuits
• Compact dimensions 127 × 70 × 57 mm with knobs
• 15 mA current draw, 9V DC negative centre barrel
• Relay–based true bypass requires isolated power supply