LooperCat — Loop Station Manager for Boss RC-5
See inside your looper. LooperCat is a companion app for the BOSS RC-5: all 99 memory slots in one table — listen, rename, trim, re-tempo, upload and download WAVs. And the app drives the pedal into STORAGE mode itself — over USB-MIDI SysEx, no nightly pilgrimage through SETUP → USB → STORAGE.
It is the fourth artifact from the planet Felitronics — and like everything we brought back from there, it is free and open-source.
Right now it’s v0.x — a beta: everything is checked against a real pedal and every write walks behind an automatic backup, but treat a beta like a beta.
What it does
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One-button connect: SysEx → STORAGE → mounted. Disconnect is just as polite: unmount and send the pedal back to looping.
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All 99 slots in one table: name, duration, bars, tempo, one-shot, WAV file. Live refresh as the pedal comes and goes.
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Listen straight from a slot: double-click — waveform, seeking, output device picker. No copying files around just to learn what lives in slot 37.
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Edit: inline rename, one-shot toggle, trim with a gapless preview of the cut, clear a slot, drag one slot onto another to swap them — and the Bars column, which fixes the tempo the RC-5 guesses wrong on odd-length loops so the onboard rhythm finally agrees with the music.
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Move audio: push a WAV into an empty or occupied slot (converted to the pedal’s native float32; the old loop goes to the app’s trash first), pull any loop out as a standard WAV.
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Stay safe: config backups before every mutation, write-generation counters — the same discipline the pedal itself keeps, junk-file hygiene for macOS droppings, a card-consistency doctor, and honest ghost detection when the pedal leaves without saying goodbye.
Download
macOS: grab the DMG from the latest release, universal binary (Apple silicon + Intel). Drag LooperCat to Applications, plug the RC-5 in over USB, press Connect. Windows is planned once the macOS release settles.
Hardware
BOSS RC-5, verified against a real unit (firmware Ver 1.10). The lineage is rc5cat: the RC-5 file format reverse-engineered, pinned by golden fixtures and verified against live hardware. The rest of the RC series — RC-500, RC-505, RC-600 — is not supported: their cards look alike, alike enough to seem compatible, but they speak a different data dialect. LooperCat checks who it is talking to and honestly refuses a foreign card instead of guessing.
LooperCat is an independent project: not affiliated with or endorsed by any hardware manufacturer; all trademarks belong to their respective owners. "BOSS RC-5" is used nominatively to state compatibility.
Frequently Asked Questions
Is LooperCat free?
Yes. Free, open-source (AGPL-3.0), no sign-ups, no subscriptions — that was the promise made on the planet Felitronics.
Which pedals are supported?
Only the BOSS RC-5 (verified on firmware Ver 1.10). The RC-500, RC-505 and RC-600 are not supported: their cards look alike but speak a different data dialect — LooperCat recognizes a foreign card and honestly refuses instead of corrupting data. Other loopers are a distant-future plan.
Do I have to go through SETUP → USB → STORAGE every time?
No. The Connect button switches the pedal into STORAGE mode itself over USB-MIDI SysEx and mounts the card; Disconnect unmounts and sends the pedal back to looping.
Is it safe for my loops?
Before every mutating operation the app backs up the configuration; replaced and deleted WAVs go to the app's trash first; write-generation counters are kept exactly the way the pedal itself keeps them. Still, v0.x is a beta: treat it like one.
Why does my loop get a wrong tempo after uploading a WAV?
When importing from the card, the RC-5 assumes a loop is a power-of-two number of measures (16, 32, 64…). Any other loop gets a wrong tempo, and the onboard rhythm drifts from the music. LooperCat makes the arithmetic visible (the Bars column) and hand-editable; automatic tempo-true upload is on the roadmap.
What is LOOPER DATA READ ERR and does LooperCat help?
It's the RC-5's boot error: the pedal trips over a broken card structure — most often macOS junk files (AppleDouble ._*) left by manual copying. LooperCat cleans that junk automatically and can check the card's consistency with its doctor.
macOS only?
For now, yes: a universal DMG (Apple silicon + Intel). A Windows build is planned once the macOS release settles.
How is LooperCat different from rc5cat?
rc5cat is the CLI and local web editor — the pioneer of the format reverse-engineering. LooperCat is a desktop app built on the same knowledge base (shared golden fixtures), plus audio — slot playback, waveforms, trimming — and control of the pedal's STORAGE mode.