Eleven XI Audio Formula SFlagship High Purity Headphone Amplifier

A Pinnacle of Acoustic Engineering

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 demanding headphone requirements, offering uncompromised control, ultra-low distortion, and a breathtakingly natural soundstage.

First Product & Recognition

The 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.

Design Philosophy

Designed with a focus on precision, musicality, and long-term listening enjoyment, it represents the core philosophy of Eleven Audio: engineering precision and musical expression. Originally developed for the legendary ABYSS AB-1266 planar headphone, it was engineered to deliver exceptional control, speed, and transparency for the most demanding high-performance headphones.

Performance Capabilities

With its powerful output capability and carefully optimized gain structure, it allows flagship headphones to reveal their full dynamic range, resolution, and musical character. Features a full Class A output stage, delivering smooth, powerful, and highly linear performance.

Design Approach

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

Signal Purity

Every part 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. It 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 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.

Sound Characteristics

The soundstage is tall, with exceptional depth and an impressive out of head width. Imaging is precise and sonic cues are detailed.