OpenRB-338 is a free, open-source standalone application that recreates the core Propellerhead ReBirth RB-338 setup on current macOS, Windows and Linux computers. Its virtual studio combines two TB-303-style bass synths with TR-808- and TR-909-style drum machines, making the compact acid-production workflow available without relying on legacy software.
The project is available now through its OpenRB-338 GitHub repository ↗ (opens in a new tab). It is an independent project by developer pingw33n, rather than software affiliated with or endorsed by Propellerhead Software or Reason Studios.
Key Takeaways
- OpenRB-338 recreates ReBirth’s two-bassline, 808 and 909-style instrument configuration as a free standalone application.
- It supports macOS on Apple Silicon and Intel, Windows on x64 and ARM64, plus Linux on x86_64 and ARM64.
- The application can open ReBirth song files, including ReBirth 1.x files and RBS 4.0 to 4.2 files from ReBirth 2.x.
- MIDI input and sync, VST, AU and ReWire support are currently listed as unimplemented, so it is not yet a conventional DAW instrument or tightly integrated live-performance tool.
- Users can export rendered loops as WAV, FLAC or Ogg Vorbis files for use elsewhere in a production.
A classic acid setup, rebuilt for current systems
Originally released in 1997, ReBirth RB-338 placed software versions of Roland-inspired bassline and drum-machine instruments into one pattern-led environment. That deliberately limited setup became a productive writing tool for acid, techno, electro and early digital dance-music workflows: programme a bass pattern, build a drum loop, arrange patterns into a song and commit the result.
OpenRB-338 follows that configuration, with the four instruments joined by a mixer, delay, distortion, PCF filter, compressor, shuffle, loop and recording functions. The interface is rendered as scalable vector graphics, intended to remain sharp at different display sizes and resolutions.
For producers, the appeal is less about replacing a full DAW than having a focused sketchpad. A dual-bassline arrangement can be useful for creating a main acid sequence plus a contrasting octave, response line or more restrained supporting pattern, while the 808/909-style drum pairing covers a familiar route to building foundational club rhythms.
The project’s documentation says its audio engine was rebuilt from ReBirth 2.01 and tested through byte-for-byte comparisons with exported loops from more than 1,200 songs. That is a technical compatibility claim from the project documentation, not an independent sound-quality assessment, but it is relevant to producers revisiting old ReBirth material.
ReBirth song-file support is the practical draw
OpenRB-338 can open ReBirth 2.x RBS songs in versions 4.0 through 4.2, as well as ReBirth 1.x song files. It can also save RBS 4.2 files that the original ReBirth application can open. That gives producers with older archives a route to revisit arrangements on supported modern operating systems rather than keeping an old computer available solely for a legacy application.
The software also supports ReBirth modification files, allowing users to load alternative drum samples and associated mod sounds. The standard drum kit is included, meaning the original installation media is not required to access that particular kit.
Once a pattern or arrangement is ready, loops can be exported in WAV, FLAC or Ogg Vorbis. In practical DAW terms, that means rendering audio and importing it into a session for arrangement, processing or mixing. Producers who want to shape the result with their existing effects chains can then use the audio as they would any other printed loop.
Standalone status limits DAW and live integration
The important limitation is that OpenRB-338 is currently standalone software. Its documentation lists MIDI input, MIDI synchronisation, VST, AU and ReWire support as unimplemented. There are also some original pattern-editing functions and undo features that are not yet available.
That means it is not currently a plug-in you can load directly into a DAW project, automate from a host, clock to a sequencer or play from a MIDI controller. Producers accustomed to using virtual instruments should not confuse it with a VST or AU instrument; Product London’s guide to VST plugins for beginner producers explains the host-based workflow those formats normally enable.
For now, OpenRB-338 makes most sense as a self-contained composition environment. Build and arrange the material inside the application, render the results, then continue production in your DAW. That approach is less immediate than MIDI-synchronised integration, but it can suit producers looking for a deliberately separate writing stage before detailed editing and mixing.
Command-line rendering could suit archives and batch work
Alongside the graphical application, the project includes a command-line tool called orb. It can render songs to audio files, play songs without the graphical interface, inspect song information, and unpack, repackage or re-encrypt modification files.
Most users will use the graphical programme, but the command-line option could be useful for people with a sizeable archive of ReBirth songs who need to render or inspect files methodically. It is also a reminder that the project is aimed at format preservation as well as recreating a familiar electronic-music instrument layout.
The original report from Synthtopia ↗ (opens in a new tab) provides further details on the project’s current feature set. Producers interested in using OpenRB-338 should treat it as a capable standalone recreation with audio-export options, rather than expecting modern plug-in hosting or MIDI-controlled performance integration at this stage.