Walrus Audio Mantle Bass Preamp/DI - Black

Built as a studio-grade solution for shaping and delivering bass tone with confidence, the Walrus Audio Mantle is a premium preamp and DI designed to anchor your sound in any environment. Developed in collaboration with session bassist and educator Ian Martin Allison, the Mantle focuses on signal integrity and musical control rather than feature overload. A pair of custom-wound Sapphire transformers inspired by classic Neve and API designs provide authoritative low-end weight, harmonic depth and up to +18 dB of gain. Paired with a refined Bass and Treble system and a transformer-balanced XLR output, Mantle presents bass tone in a controlled, finished form whether you are tracking direct or playing live.

Custom Sapphire Transformers With Studio-Grade Harmonic Depth

At the core of the Mantle are Walrus Audio’s proprietary Sapphire transformers, carefully voiced to capture the musical strengths of revered studio preamps. The input transformer delivers a strong, quiet signal with focused low-end authority and midrange presence, while the output transformer adds clarity, balance and subtle harmonic richness. Together, they create a dimensional tone that enhances your instrument without masking its natural character.

High-Headroom JFET Design for Dynamic, Touch-Sensitive Response

The Mantle features a high-impedance JFET input buffer that preserves feel and responsiveness across a wide range of playing styles and instruments. Internally boosted to +24V, the circuit offers exceptional headroom, allowing deep lows and aggressive transients to pass cleanly without compression or strain. This design keeps the Mantle feeling immediate and articulate, from passive vintage basses to modern active instruments.

Musical Gain, Smart EQ and Flexible Studio-to-Stage Routing

Mantle’s transformer-based gain control spans from -9dB to +18dB, supporting everything from subtle enhancement to harmonically rich amplification. The Bass and Treble controls use a boost-and-cut system that shifts from smooth shelving to precision filtering for intentional tone shaping, while 11-position rotary switches provide repeatable studio-style control with a true flat response at noon. A transformer-balanced XLR output, 1/4" amp output, active and passive padding and ground lift ensure seamless integration into studio sessions, live rigs and hybrid setups. Whether it serves as an always-on front end or a dedicated tone-shaping tool, Mantle delivers a refined, authoritative bass sound you can trust in any environment.