The first sound effects built into amplifiers were tremolo and reverb. Keeley's legendary reverbs are paired with their sultry, vocal-like tremolos to give you an unreal sonic experience.

Zoma Key Features
- Simple Control Layout: Three large knobs give you maximum control over Reverb Level and Rate and Depth for Tremolo.
- Easy Access Alt-Controls: Reverb Decay, Reverb Tone, Tremolo Volume.
- Instant Effect Order Switching: Choose which signal path is right for you. Put your tremolos after the reverb for a vintage correct, black-panel tone. Experience a dirty, swampy tone with harmonic tremolo on top of reverb.
- True Bypass or Buffered Trails: You chose what sounds and works best in your rig.

3 Reverb and Trem Modes:
- SS - Spring Reverb and Sine Tremolo - Classic black panel amplifiers had spring reverb followed by a sine wave tremolo (at the power tubes)
- PH - Plate Reverb and Harmonic Tremolo - Smooth reverb with swampy harmonic trem, what's not to love?
- PV - Plate Reverb and Pitch Vibrato - Vocal smooth vibrato with other-worldly reverb.

Reverb - Sounds and Controls
- Spring Reverb: tube amp spring reverb - we simulate every detail of that classic vintage reverb sound.
- Plate Reverb: bright, smooth reverb from a thin vibrating metal plate.
- Reverb Decay: (Alt feature) Hold REVERB/ALT SWITCH down while adjusting Level knob.
- Reverb Tone: (Alt feature) Hold REVERB/ALT SWITCH down while adjusting Rate knob.

Tremolo - Sounds and Controls
- Sine Wave or Volume Tremolo: Sine wave tremolo simply adjusts the volume of the signal up and down.
- Harmonic Tremolo: Just like tube-amp harmonic tremolo, your guitar signal is phase-split and filtered, almost like a phaser.
- Pitch Vibrato: Bends the notes out of tune, you control how far and how fast.
- Alt-Control-Tremolo Boost Volume: Hold REVERB/ALT footswitch down while adjusting Depth knob.

Zoma Highlights
- Reverb: Experience the ultimate reverb with the Keeley ZOMA, featuring two immersive modes: the lush, vintage-inspired Spring Reverb and the rich, expansive Plate Reverb-delivering true stereo sound that transforms your tone with precision and depth.
- Tremolo: Immerse yourself in the rich textures of the Keeley ZOMA's three distinct tremolo modes: classic Sine Wave Tremolo, vibrant Harmonic Tremolo, and dynamic Pitch Vibrato-crafted for true stereo sound and unmatched tonal versatility.