BOSS ACS-PRO 120W Acoustic Guitar/Vocal Combo Amplifier

The BOSS ACS-PRO Acoustic Singer Pro is a 120-watt acoustic combo amplifier designed for singer-guitarists who need guitar and vocal amplification from one compact stage rig. Its separate guitar and microphone channels help simplify solo performance setups while providing dedicated controls for each source. The amp is suited to practice, songwriting, small-stage performance, and use as a personal monitor with a PA system.

A bi-amp power section drives a custom 8-inch woofer and 1-inch dome tweeter for clear, full-range acoustic instrument and vocal reproduction. The guitar and mic channels each use discrete analog input circuitry and three-band EQ, allowing players to shape each signal independently. Dedicated anti-feedback and phase controls on both channels support more controlled operation in live environments.

The guitar channel includes BOSS Acoustic Resonance processing, designed to restore natural resonance and reduce the hard character commonly associated with piezo-equipped stage guitars. It also provides chorus and reverb effects for adding depth without requiring external processors. The microphone channel includes delay/echo, reverb, and selectable phantom power for compatible condenser microphones.

For vocal performers, the onboard Harmony function analyzes the guitar input in real time to create harmonies that follow the song's key and chord movement. High, low, and unison harmony settings are available, while the built-in looper supports layered guitar, vocal, and effects-based parts. These functions can be controlled from the amplifier or with compatible foot control options.

The ACS-PRO can work as a self-contained acoustic performance amplifier or integrate with larger systems through its dual XLR DI/line outputs. The outputs can be assigned for separate channel feeds or a mixed signal, with direct or post-effects routing options. An aux input, headphones/record output, and USB Type-B connection expand its usefulness for backing tracks, quiet practice, portable recording, and computer-based recording.

Key Features

• 120-Watt Bi-Amp Design: Separately powers the woofer and tweeter for acoustic guitar and vocal reinforcement.
• Dual Independent Channels: Provides dedicated guitar and mic inputs with separate three-band EQ sections.
• Acoustic Resonance: Helps restore a more natural, resonant sound from piezo-equipped acoustic guitars.
• Automatic Vocal Harmony: Creates harmonies by analyzing the guitar input in real time.
• Built-In Looper: Lets performers build layered backing parts with guitar, vocals, and effects.
• Flexible Stage Outputs: Dual XLR DI/line outputs support mixed or separately assigned signals for PA connection.

Design & Installation

The ACS-PRO uses a compact combo-amp enclosure with an integrated tilt-back design for improved sound projection toward the player and audience. Its speaker system combines one custom 8-inch woofer with one 1-inch dome tweeter. The amplifier measures 16-7/16 inches wide, 13 inches deep, and 14-1/8 inches high, with a listed weight of 32 pounds.

Connect an acoustic guitar to the 1/4-inch guitar input and a vocal microphone or compatible second source to the XLR/1/4-inch TRS combo mic input. Use the anti-feedback, phase, EQ, and level controls to tailor each channel for the room, then connect the XLR DI/line outputs to a PA when additional coverage is needed. The included dual footswitch controls looper and harmony functions; additional compatible BOSS footswitches, an expression pedal, and the Roland GA-FC are available separately.