Pymss vs StemDeck

Pymss is an open-source music source-separation toolchain that runs on the user's own machine and separates audio into vocals, drums, bass, and other stems. Its Studio desktop workspace handles model management, batch jobs, and stem editing. Users can import files or folders, choose a downloaded model, configure inference, and queue work. Studio can browse, download, resume, and delete model files, with storage cleanup controls. Waveform previews, mix controls, saved projects, and stem export support work on the results. Pymss can chain models so each workflow step uses the preceding step's output. The inference package lists WAV, FLAC, MP3, M4A, AAC, Opus, Vorbis, and Ogg output. Other components include ComfyUI custom nodes, a VST3 ARA plugin for compatible DAWs, and a browser interface bundled with the server. The ARA plugin provides per-stem mute and solo controls; its README gives Reaper and Studio One as host examples. The repositories have separate licenses: Studio is listed under AGPL-3.0 and the inference package under MIT. Studio remains at an early development stage, and changes between versions may break things.

StemDeck separates songs into stems for practice, study, transcription, remixing, and other creative audio work. Its Demucs htdemucs_6s model separates vocals, drums, bass, guitar, piano, and other sounds. Files accepted include MP3, WAV, FLAC, OGG/Opus, MP4, and M4A, and songs can also be supplied by YouTube URL. The workspace provides waveform lanes, mute and solo controls, volume adjustment, and looping; users can export individual stems or a custom mix in WAV or MP3. Song analysis includes BPM, key, scale, confidence, integrated LUFS, and sample peak level. StemDeck says audio processing runs locally and the app does not transmit, store, cache, or redistribute audio. Internet access is needed for YouTube downloads and an initial model fetch of about 170 MB, which is cached afterward. The project documents Docker and Unraid deployment, source-based web-server use, and a local REST API. It is free, with no account, quota, uploads, or subscription, but handles one job at a time, supports up to six stems, and has no mobile app.