Stompbox wizard Robert Keeley’s latest creation packs a boatload of deep-sea diver sounds in one small package.

The Hydra Stereo Reverb & Tremolo offers three reverb algorithms (Room, Plate, and Spring) and three tremolo patches (Sine, Vibrato, and Harmonic), while an infinite reverb trail setting produces sustained textures.

In addition to user-friendly tone-shaping controls, the Hydra has three pre-sets that allow guitarists to access and capture their favorite tonal combinations. The tremolo controls include Rate and Depth, while the reverb side offers Dwell, Mix, and Color knobs. Others allow users to rearrange the order of effects or alter the effects’ personalities. An expression pedal can be used in place of the onboard tap tempo or be assigned to other knobs. There’s even remote switching for rack users.

The wild, pitch-warbling vibrato is fun, but it’s the subtle ambient coloring that truly shines. Each setting can be modified to alter the tone and size, along with tail length, speed, and depth. The Hydra can also be set up for true bypass or buffered bypass with trails. The overall quality is smooth, warm, lush, and dreamy. Powered by a 9-volt adapter, the Hydra is simple to use and will add fullness and dimension to any signal.

This article originally appeared in VG’s May 2021 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.