BOSS GM-800 Guitar Synthesizer

The BOSS GM-800 is a guitar and bass synthesizer that turns compatible divided-pickup performance data into detailed ZEN-Core instrument and synth sounds. It is designed for players who want to add keyboard-style voices, layered textures, rhythm sounds, and alternate musical roles without leaving their guitar or bass workflow. A required Serial GK-compatible pickup system captures each string independently for the GM-800’s sound engine.

At its core, the GM-800 uses the ZEN-Core sound generator found in modern Roland synthesizer products. Its onboard library includes more than 1,200 preset Tones and 70 or more preset drum kits, covering acoustic instruments, electronic sounds, and classic-style synth voices. Four playable Tone parts and one Rhythm part can be combined within a single Scene for layered or split-style performance setups.

The GM-800 is built for expressive playing rather than conventional guitar effects processing alone. Individual Tones can be assigned by string or fret range, allowing low strings and high strings to trigger different musical roles. High-performance DSP supports pitch and string tracking, while pickup sensitivity settings help tailor response to the installed instrument.

Scenes store the sound selections, edits, effects, control assignments, and performance settings needed for a song or playing situation. The unit provides 150 user-configurable Scenes, with 100 ready-to-play Scenes supplied from the factory. Each part has its own multi-effects and EQ processing, while shared Scene effects, chorus/delay, reverb, master EQ, and compression provide additional sound shaping.

For expanded rigs, the GM-800 connects to amplifiers, line-level systems, mixers, headphones, computers, USB flash drives, MIDI devices, and external foot controls. It supports USB audio and MIDI for recording and software-instrument use, plus Guitar to MIDI for controlling external MIDI equipment. The compact format works on a pedalboard or desktop, making it suitable as a dedicated synth voice source within a guitar, bass, recording, or MIDI setup.

Key Features

• ZEN-Core Sound Engine: Provides modern PCM synthesis and modeling-based instrument and synth sounds.
• Serial GK Interface: Accepts compatible BOSS divided-pickup signals for per-string performance tracking.
• Five-Part Structure: Combines four playable Tone parts with one Rhythm part.
• Extensive Sound Library: Includes 1,200 or more preset Tones and 70 or more drum kits.
• Scene-Based Workflow: Stores complete sound, effect, control, and performance configurations.
• USB And MIDI Connectivity: Integrates with computers, MIDI hardware, and external sound modules.

Design & Installation

The GM-800 uses a compact pedal-format layout with a graphic LCD, dedicated part buttons, assignable footswitches, editing knobs, and an output-level control. BOSS specifies a 246 mm wide enclosure and includes four rubber feet for placement protection and stability. The manufacturer does not publish an enclosure-material specification.

Installation requires a guitar or bass with a compatible divided pickup, such as the BOSS GK-5 or GK-5B, connected with a dedicated BGK Serial GK cable. Older 13-pin GK pickup systems can be used through the optional GKC-AD converter. Connect the output to a guitar amp, line-level system, mixer, or headphones as appropriate, and use the USB or five-pin MIDI ports when integrating computer or MIDI hardware workflows.