# Valeton GP-50 Editor: live preset editing over reconstructed SysEx

> Valeton GP-50 Editor controls GP-50 and GP-5 guitar pedals through a reconstructed MIDI SysEx protocol. Its browser interface uses WebMIDI to inspect and edit presets, reorder blocks, rename slots and convert GP-5 and GP-50 .prst files. The repository also includes protocol tooling and findings about the vendor's NAM-to-SnapTone conversion path.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/drewmerc302/valeton-gp50>
- Primary source: <https://github.com/drewmerc302/valeton-gp50/blob/47b2b583bc9b2ba8936fe247ae29af790c6dc6a3/README.md>
- Catalog page: <https://awesomerea.org/resources/valeton-gp50-editor-case/>
- Record JSON: <https://awesomerea.org/resources/valeton-gp50-editor-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/valeton-gp50-editor-case/index.md)

## Requirements & limits

- **Prerequisites:** A GP-50 or GP-5 connected by USB and a WebMIDI-capable Chrome or Edge browser are required for live editing.
- **Limits:** Chrome 152 has a documented SysEx framing regression; the source recommends Chrome 153 or newer.
- **Testing evidence:** The author no longer owns test hardware, so later device I/O changes are checked against tests rather than a live pedal.
- **License:** MIT license.

## Primary sources

1. <https://github.com/drewmerc302/valeton-gp50/blob/47b2b583bc9b2ba8936fe247ae29af790c6dc6a3/README.md>
2. <https://github.com/drewmerc302/valeton-gp50/blob/47b2b583bc9b2ba8936fe247ae29af790c6dc6a3/re/REFIT_FINDINGS.md>
3. <https://github.com/drewmerc302/valeton-gp50/blob/47b2b583bc9b2ba8936fe247ae29af790c6dc6a3/LICENSE>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.