Formula S
Flagship High Purity Headphone Amplifier

The Formula S Headphone Amplifier by Eleven Audio stands as a pinnacle of acoustic engineering, specifically crafted for the most discerning audiophiles. As a premier high end headphone amplifier, this dedicated Class A headphone amplifier features a full balanced headphone amplifier output stage designed to unleash the absolute maximum potential of flagship headphones. Most notably, its high-current delivery provides the legendary synergy required to perfectly master the ABYSS AB-1266 Amplifier demands, offering uncompromised control, ultra-low distortion, and a breathtakingly natural soundstage.

The First Statement Product from Eleven Audio

Formula S is the very first product created by Eleven Audio.
Combining exceptional sonic performance with outstanding driving capability, it quickly gained worldwide recognition and became a highly regarded amplifier among headphone Hi-Fi enthusiasts.

Designed with a focus on precision, musicality, and long-term listening enjoyment, Formula S represents the core philosophy of Eleven Audio: engineering precision and musical expression.

Designed for the Most Demanding Headphones

Originally developed for the legendary ABYSS AB-1266 planar headphone, Formula S was engineered to deliver exceptional control, speed, and transparency for the most demanding high-performance headphones.

With its powerful output capability and carefully optimized gain structure, Formula S allows flagship headphones to reveal their full dynamic range, resolution, and musical character.

Pure Class A Performance

Formula S features a full Class A output stage, delivering smooth, powerful, and highly linear performance.

The design prioritizes low distortion, precise transient response, and natural harmonic richness — achieving the refinement and musicality often associated with high-performance tube amplification, without the heat and maintenance.

Dual Mono Architecture

The dual mono amplifier design separates left and right channel amplification modules, minimizing interference and maximizing channel separation, imaging accuracy, and soundstage stability.

Precision Engineering for Pure Signal Integrity

Every part of Formula S is designed with signal purity in mind.

The amplifier uses premium components, a direct signal path, and carefully selected internal wiring to preserve the integrity of the original recording.

Precision Volume Control

Formula S incorporates a high-quality ALPS volume control system, carefully optimized to maintain excellent channel balance and resolution even at lower listening levels.

ABYSS Edition

The ABYSS Edition Formula S was specially tuned for the ABYSS AB-1266 headphone.

Featuring internal wiring by JPS Labs, this edition further enhances the amplifier’s ability to deliver the speed, bass authority, and micro-detail required by the world’s most demanding headphones.

Awards & Recognition

Formula S has received international recognition from the high-end audio community, including:

▸ 12-Time VGP Award Winner
▸ Audio Excellence Award Recipient
▸ Highest rating among headphone amplifiers in The Absolute Sound / Hi-Fi+ Ultimate Headphone Guide

Specifications

Unlock the Full Potential of Formula S

For listeners seeking the ultimate performance from Formula S, Powerman™ provides a dedicated external high-current linear power supply designed to replace the amplifier's internal power source.

With ultra-low-noise discrete regulation and a large toroidal transformer, Powerman™ delivers greater energy reserve, improved dynamics, deeper soundstage, and enhanced musical detail.

Explore Powerman™ ➔