2.3 Roland Converters: BOSS SY-1000 and BOSS GM-800

BOSS, a brand of the Roland Corporation, has released two devices of particular relevance to the present research: the BOSS SY-1000 (2019) and the BOSS GM-800 (2023). Both are guitar synthesizers designed for audio and MIDI sound synthesis and, despite their differing technical characteristics, are functionally comparable with regard to their implementation of the MIDI Out protocol.

From a hardware-interface perspective, the two devices belong to distinct technological generations. The SY-1000 employs the traditional 13-pin analog DIN connector, maintaining continuity with Roland’s GK/GR product family developed over recent decades: the signal from the divided pickup is transmitted in analog form from the pickup to the converter. The GM-800, by contrast, introduces a new proprietary digital interface known as Serial GK, which carries the pickup signal in digital format via a dedicated cable.

The native pickups designed for the Serial GK system are the GK-5 (guitar) and GK-5B (bass), connected through BGK-15 or BGK-30 cables. For users employing traditional 13-pin pickups—such as the Roland GK-3 or GK-3B—the GKC-AD adapter is available, converting the analog signal into the digital Serial GK format. The reverse conversion is also possible through the GKC-DA, enabling the GM-800 to control 13-pin devices such as the SY-1000 and thereby ensuring backward compatibility with the pre-existing analog ecosystem. Both converters support piezoelectric pickups among their configurable options, including the PIEZO R setting (the designation used for RMC systems), which is available on both devices.

Regarding analog-to-digital conversion, the SY-1000 operates at 32-bit resolution with a 48 kHz sampling rate, employing the AF (Adaptive Focus) method, a proprietary Roland/BOSS technology designed to optimize the signal-to-noise ratio of the conversion stage. The GM-800, which is physically more compact (246 × 134 × 63 mm compared with the SY-1000’s 345 × 245 × 67 mm, and weighing 1.2 kg versus 2.5 kg), does not provide detailed A/D conversion specifications in its reference documentation. However, Roland’s official press release of July 20, 2023, describes its architecture as the integration of three distinct technologies: the Serial GK digital interface, a high-performance DSP dedicated to pitch detection, and the ZEN-Core synthesis engine

Assignment of Monophonic Outputs on the GM-800
 

It is important to distinguish between these two functional blocks, as they are often confused in non-specialist literature. ZEN-Core is exclusively the sound engine operating downstream from the conversion process: a PCM- and modeling-based synthesis system that, in the GM-800, provides access to more than 1,200 Tones, including acoustic instruments, organs, pianos, and classic synthesizers such as the JUPITER-8 and JUNO-106. The same engine is also found in other professional Roland products, including the JUPITER-X, FANTOM, and the ZENOLOGY software platform. The pitch-detection DSP, by contrast, is the component that receives the signal from the pickup and generates the MIDI data.

The GM-800’s memory architecture is organized around the concept of a Scene. Each Scene can contain up to four tonal parts assigned to ZEN-Core Tones, one rhythm part, synthesis parameters, effects, pitch settings, and sensitivity adjustments. Tones may be assigned to specific strings—for example, a bass sound on the lower strings and a piano sound on the upper strings—or, uniquely to the GM-800, to specific fret ranges, a feature made possible by the device’s advanced pitch-detection technology.

The SY-1000, by contrast, organizes its signal flow around the concept of a Patch, each of which contains three independent INST blocks with a fully reconfigurable effects chain. The system provides a total of 200 preset patches and 200 user patches for each operating mode (guitar and bass). Both devices support USB connectivity for audio and MIDI transmission, physical MIDI IN and OUT/THRU connectors, and inputs for footswitches and expression pedals.  

SY 1000 (2019)
 https://www.boss.info/global/products/sy-1000/ 

 

 

GM 800 (2023)
 https://www.boss.info/it/products/gm-800/