# Preset Forge — Valeton GP-200 Preset Editor

> Free browser-based editor for Valeton GP-200 guitar multi-effects presets. The only GP-200 editor that runs on Linux (tested on Linux Mint). Works on Windows, macOS, Linux, and Chrome OS — no installation required.

Preset Forge is an open-source web application for editing Valeton GP-200 .prst preset files in the browser. The official Valeton GP-200 editor software is Windows-only and does not run on Linux. Preset Forge fills this gap: it runs in any modern browser, works offline as a PWA, and supports live USB MIDI editing via the Web MIDI API (Chrome/Chromium required for MIDI).

Key facts:
- Supports all 305 GP-200 effects with real parameter controls (up to 15 parameters per effect)
- .prst binary format: exactly 1224 bytes, 11 effect slots, reverse-engineered from the official Valeton software
- USB MIDI SysEx protocol: 14 message types, fully reverse-engineered and hardware-verified with firmware 1.8.0
- Imports Line6 HX Stomp .hlx preset files and converts them to GP-200 format (experimental)
- Community preset gallery with per-effect filtering across 305 effects in 12 modules
- Auto-generated landing page for each real-world amp model that community presets are based on (Marshall, Fender, Mesa/Boogie, Vox, Bogner, and more)
- Live setlists with timed cue points for automatic preset switching during gigs
- MIDI auto-reconnect (3 attempts) if USB connection drops during performance
- Free, no account needed to use the editor or browse the gallery
- Available in 7 languages: English, German, Spanish, French, Italian, Portuguese (PT + BR)

## Editor

- [GP-200 Preset Editor](https://www.preset-forge.com/editor): Load .prst files, edit all 11 effect slots, adjust parameters, drag-and-drop reorder the signal chain. Push changes live to the device via USB MIDI. Works on Linux, Windows, macOS.

## Help & Documentation

- [Help & FAQ](https://www.preset-forge.com/help): Getting started, USB MIDI setup (Linux/Windows/macOS), HX Stomp import guide, playlist and cue point documentation, keyboard shortcuts, and FAQ including Linux support details.

## Community

- [Preset Gallery](https://www.preset-forge.com/gallery): Browse, download, and share GP-200 presets. Filter by module type and individual effect across all 305 supported effects.

## Presets by Amp Model

Each real-world amp that community presets are modelled on has its own landing page listing every matching GP-200 preset, with the Valeton model name mapped back to the original gear it emulates.

- [Marshall JCM800 presets](https://www.preset-forge.com/amp/marshall-jcm800)
- [Fender '65 Twin Reverb presets](https://www.preset-forge.com/amp/fender-65-twin-reverb)
- [Mesa/Boogie Dual Rectifier presets](https://www.preset-forge.com/amp/mesa-boogie-dual-rectifier-modern-mode)
- [Roland JC-120 Jazz Chorus presets](https://www.preset-forge.com/amp/roland-jc-120-jazz-chorus-solid-state-combo)

## Technical

- [GitHub Repository](https://github.com/phash/gp200editor): Open-source (Next.js 15, React 19, TypeScript, Prisma, Lucia v3). Includes full .prst binary format documentation, the reverse-engineered SysEx protocol (14 message types), and a comprehensive unit + end-to-end (Playwright + axe) test suite.

## Optional

- [Legal Notice](https://www.preset-forge.com/legal): Impressum / legal information.
- [Preset Gallery (German)](https://www.preset-forge.com/de/gallery): German-language gallery.
- [Help (German)](https://www.preset-forge.com/de/help): German-language help and FAQ.