Boss ACS-LIVE & ACS-PRO Acoustic Amplifier User Manual

Boss ACS-LIVE & ACS-PRO Acoustic Amplifier Manual

Introduction

The boss ACS-LIVE & ACS-PRO Acoustic Amplifier series is designed for acoustic guitarists, singer-songwriters, vocalists, teachers, and small performance setups that need detailed, natural sound in a portable combo amplifier. Both models combine a dedicated guitar channel with an independent microphone channel, allowing one performer to amplify an acoustic instrument and vocal microphone through a single system.

The ACS-LIVE delivers a 60-watt bi-amped design with a 6.5-inch woofer and dome tweeter, while the ACS-PRO provides 120 watts with a larger 8-inch woofer for greater headroom and projection. Each channel includes a three-band equalizer, level control, anti-feedback facilities, and effects suited to acoustic performance. The guitar channel includes Acoustic Resonance processing to help restore a more natural response when using piezo pickups. The microphone channel supports phantom power for compatible condenser microphones.

Additional performance tools include guitar chorus, vocal delay or echo, reverb, harmony generation, and a built-in looper. Separate XLR outputs support connection to a mixing console, audio interface, or recording system. USB connectivity and a headphone or recording output also make the amplifier useful for practice and direct recording.

Choose the ACS-LIVE for rehearsals, coffeehouses, teaching, and intimate venues. Choose the ACS-PRO when higher volume, larger rooms, and additional clean headroom are priorities.

Specifications and Key Features

The following specifications describe the standard ACS-LIVE and ACS-PRO acoustic amplifier models. Controls and functions may vary by production version or regional configuration.

• Amplifier design: Two-channel bi-amped acoustic amplifier with separate woofer and tweeter amplification.
• ACS-LIVE power: 60 watts total, divided between a 50-watt woofer section and a 10-watt tweeter section.
• ACS-PRO power: 120 watts total, divided between a 100-watt woofer section and a 20-watt tweeter section.
• ACS-LIVE speaker system: One 6.5-inch woofer and one 1-inch dome tweeter.
• ACS-PRO speaker system: One 8-inch woofer and one 1-inch dome tweeter.
• Channels: Independent guitar and microphone channels with separate three-band equalizers.
• Guitar processing: Acoustic Resonance and chorus.
• Microphone processing: Phantom power, delay or echo, and vocal harmony functions.
• Feedback control: Independent anti-feedback controls for the guitar and microphone channels.
• Inputs: Guitar input, XLR/quarter-inch microphone input, and stereo auxiliary input.
• Outputs: Separate XLR DI/line outputs, stereo headphones or recording output, and USB computer connection.
• Foot control: Connections for compatible looper, chorus, harmony, mute, and GA-FC control functions.
• ACS-LIVE size and weight: Approximately 367 × 274 × 314 mm and 10.5 kg.

How to Set Up the Boss ACS-LIVE & ACS-PRO Acoustic Amplifier

1. Place the amplifier on a stable, dry surface with clear space around the ventilation openings. Keep it away from water, excessive heat, and direct sunlight.
2. Turn the master volume down and switch the amplifier off before making connections.
3. Connect an acoustic guitar to the guitar input using a suitable quarter-inch instrument cable.
4. Connect a dynamic microphone or compatible condenser microphone to the microphone input. Enable phantom power only when the connected microphone requires it.
5. Connect an optional phone, music player, or backing-track source to the stereo auxiliary input. Set the source volume conservatively before raising the amplifier level.
6. Connect the supplied power cable, switch on the amplifier, and slowly raise the guitar, microphone, and master levels.
7. Set the three-band equalizers near their center positions, then adjust bass, middle, and treble for the room and instrument.
8. Use Acoustic Resonance for a piezo-equipped guitar when a fuller, less direct pickup character is needed.
9. Activate chorus, reverb, delay, harmony, or looping only after establishing a clean basic sound.
10. For a sound system, connect the appropriate XLR DI outputs and select whether the signal should be direct, effect-processed, individual, or mixed.

If feedback occurs, reduce the affected channel level, reposition the microphone or amplifier, and adjust the relevant anti-feedback control. Never connect or disconnect cables at high volume, and keep phantom power off while plugging or unplugging microphones.

Troubleshooting the ACS-LIVE and ACS-PRO

No sound from the guitar

Confirm that the guitar cable is fully inserted, the instrument volume is raised, and the guitar channel level is above zero. Replace the cable or battery if the guitar uses active electronics. Check that the master volume is not muted.

No microphone signal

Verify that the microphone is connected to the microphone input rather than the guitar input. Raise the microphone channel level and check the microphone’s switch. Enable phantom power only for a microphone that needs it. If a dynamic microphone is being used, phantom power is generally unnecessary.

Acoustic feedback or howling

Lower the affected channel, move the microphone away from the speaker, avoid pointing the microphone toward the amplifier, and use the channel’s anti-feedback controls. Excessive low-frequency boost can also increase feedback.

Effects or harmony do not operate

Check that the effect level is raised and that a compatible foot controller is connected to the correct control jack. Harmony requires a usable guitar signal for chord or key detection, so play clear chords and avoid excessive distortion or noise.

USB or recording output problems

Use a suitable USB cable, select the amplifier as the input device in the recording software, and confirm that the software track is armed. For headphone recording, check the output level and the selected signal routing.

Support and preventive care

No universal error-code list is specified for these amplifier models. If the amplifier remains silent, overheats, produces abnormal noise, or shows physical damage, switch it off and disconnect the power. Do not open the cabinet. Consult the official BOSS support site, the owner’s manual, or an authorized BOSS service center for model-specific assistance and warranty procedures.

Pros and Cons

Advantages

• Two-channel convenience: Guitar and vocals can be amplified independently, making the system practical for solo performers.
• Natural acoustic response: Acoustic Resonance can help reduce the hard or nasal character sometimes associated with piezo pickups.
• Performance-focused effects: Chorus, reverb, delay, harmony, and looping provide more flexibility than a basic acoustic combo.
• Professional connectivity: Separate XLR outputs support direct connection to a mixer or front-of-house system.
• Recording capability: USB and headphone or recording outputs make practice and demo recording straightforward.
• Model choice: The ACS-LIVE is easier to manage for smaller spaces, while the ACS-PRO offers more power and low-frequency projection.

Limitations

• Limited channel count: Players needing several instruments, multiple microphones, or extensive routing may need a mixer and separate PA system.
• Size and weight: The ACS-PRO is less convenient than a compact practice amplifier when frequent stair or public-transport travel is involved.
• Effects are performance-oriented: Users seeking deep studio-style editing or programmable multi-effects may prefer dedicated processors.
• Feedback still requires placement: Anti-feedback controls help, but poor microphone positioning or excessive volume can still cause feedback.

The boss ACS-LIVE & ACS-PRO Acoustic Amplifier suits acoustic performers who want one integrated system for guitar, vocals, effects, and direct output. Players who need a full band PA, extensive mixer routing, or highly portable battery operation may require a different product category.