PD Cleaner

A vintage-styled VST3 plugin and standalone application for restoring early public-domain recordings — acoustic-era 78 rpm discs, wax cylinders, and shellac (pre-1926). It removes clicks, crackle, broadband hiss, hum, and rumble using classical DSP, adds an era-aware playback-EQ stage, and presents it all through a 1920s-laboratory interface designed to be approachable for non-engineers.

Download: latest release · Website: live site (source)

Two products, one engine

• Standalone — drag in a recording, ride a single Clean knob (or fine-tune with the advanced controls), audition A/B and "hear only what was removed", then export a restored copy. Batch folder processing is included, and your original file is never modified.
• VST3 — the same restoration as a real-time insert in any DAW, plus a drag-in audition station. Every control has a true neutral position: at rest the plugin is bit-for-bit transparent, and the sound only changes once you move a control.

The restoration chain

Rumble high-pass → de-hum → de-click → de-crackle → broadband denoise → era playback-EQ / de-resonance / band-limit → optional "Character" voicing.

The detection and repair stages adopt published ideas from the 78 rpm restoration community (wavelet band-splitting, outlier detection, per-sample crackle attenuation, pitch protection, reverse processing) alongside MMSE / OM-LSA spectral denoising.

Building from source

Requirements: CMake ≥ 3.22, a C++20 compiler (MSVC on Windows), and a JUCE 8 checkout.

cmake -B build -DPDC_JUCE_DIR="/path/to/JUCE"
cmake --build build --config Release

This builds the standalone app (PDCWorkbench), the VST3 (PDCleanerVST), the pdclean command-line tool, and the test suite. The core DSP library (src/dsp, src/engine) is JUCE-free and is exercised independently by a Catch2 suite under tests/.

Optional encoders

WAV / AIFF / FLAC / Ogg import and export work out of the box. MP3 / AAC / Opus export and exotic-format import are enabled by placing lame and/or ffmpeg next to the executable (or in the app-data bin/ folder) — they are invoked as external tools and are never compiled in.

License

PD Cleaner is free software, licensed under the GNU Affero General Public License v3.0 — see LICENSE. It is built with JUCE, used here under JUCE's AGPLv3 option.

Copyright (C) 2026 Wiseman.

Credits

• In tribute to Brian Davies, whose ClickRepair the 78 rpm community relied on for years.
• Typefaces: Jost* and Old Standard TT, under the SIL Open Font License.
• FFT: pffft (BSD-style). Tests: Catch2 (BSL-1.0).