Boss RC-5 editor and loop manager — LooperCat
v0.9.3 what's new
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, import and export WAVs. A slot name is typed on a real keyboard instead of scrolled with a knob — twelve characters, ninety-nine slots, an evening of your life. 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 → a flash drive. Disconnect is just as polite: eject the card 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. A lamp in the row is the setting: clicking it flips that setting straight from the table, and which lamps stay in sight is your call. Live refresh as the pedal comes and goes.
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Listen straight from a slot: double-click — waveform, seeking, a preview volume fader, output device picker. No copying files around just to learn what lives in slot 37.
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Edit: the Properties pane under the table — a name of twelve characters (exactly what the pedal’s display holds), tempo with the bar count that follows from it, Play Count-In, one-shot; and in the table itself — inline rename, trim with a gapless preview of the cut, clear a slot, drag one slot onto another to swap them. Plus the Bars column, which fixes the tempo the RC-5 guesses wrong on odd-length loops: LooperCat writes tempo and bars together so the onboard rhythm finally agrees with the music.
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Move audio: push any WAV into an empty or occupied slot — converted on the way in to the format the pedal actually wants (sample rate, bit depth, channels, header bytes), so a bounce straight out of your DAW — or a ready-made backing track — becomes a loop: a float mix is native to the pedal, everything else is recomputed on the way in; the old one goes to the app’s trash first. Pull any loop out as a standard WAV.
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Walk on stage: Play Count-In — the pedal beats one measure of count and then rolls into the loop, so a backing track is stage-ready in one tap.
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Stay safe: config backups before every mutation, write-generation counters — the same discipline the pedal itself keeps, a sweep for the macOS invisibles (
._*,.DS_Store) that Finder itself leaves underfoot, a card-consistency doctor, and honest ghost detection when the pedal leaves without saying goodbye. The backup and the sweep answer by hand too — for a card that lived a life before LooperCat.
Download
Both builds live in the latest release. What is new in it, and what came before — the changelog, version by version.
macOS: the DMG, universal binary (Apple silicon + Intel), signed and notarized. Drag LooperCat to Applications, connect the RC-5 to your computer over USB, press Connect.
Windows: a portable exe in a zip — no installer, no admin rights, no VC++ redistributable. Unzip anywhere and run. It is not code-signed yet, so the first launch of a downloaded build meets SmartScreen: More info → Run anyway, once.
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.
How do I put the Boss RC-5 into STORAGE mode?
Press Connect: LooperCat switches the pedal into STORAGE mode itself over USB-MIDI SysEx and mounts the card; Disconnect unmounts and sends the pedal back to looping. By hand it is the SETUP → USB → STORAGE path on the pedal — a walk you no longer have to take every evening.
How do I import a WAV or a backing track into the Boss RC-5?
Push WAV here… on an empty slot, Replace WAV… on an occupied one — and that's it: the file is brought to the pedal's format, the slot config is written together with the audio, the old loop goes to the app's trash. By hand it means copying onto the mounted card — and that is where macOS quietly drops an invisible ._ file next to yours, the one the pedal trips over at the next boot.
What WAV format does the Boss RC-5 accept?
The pedal records in 44.1 kHz stereo 32-bit float itself — so a plain float mix out of your DAW is native to it, nothing to convert. Roland's import documentation adds 16- and 24-bit PCM at the same 44.1. Anything past that — your project's 48 kHz, say — LooperCat recomputes on upload.
Is LooperCat safe for my Boss RC-5 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 is the tempo wrong after I import a WAV into the Boss RC-5?
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.
My computer doesn’t see the Boss RC-5 — what should I check?
The pedal becomes a drive only in STORAGE mode — LooperCat drives it there itself, with Connect. If there is still no drive, it's the cable: half the USB cords in the house are charge-only, with no data lines, and the pedal stays silent in those. And plug it in directly, without a hub.
Is there a Windows version?
Yes, since v0.9.3: a portable exe in a zip — no installer, no admin rights, no VC++ redistributable. It is not code-signed yet, so the first launch meets SmartScreen: More info → Run anyway. The macOS build is a universal DMG (Apple silicon + Intel), signed and notarized.
How is LooperCat different from the official BOSS app?
BOSS TONE STUDIO for RC does exactly one thing — upload a WAV — and fills the rest of the screen with videos nobody asked for: no slot naming, no diagnostics. LooperCat is everything else: names (typed, not scrolled with a knob — twelve characters, ninety-nine slots), tempo and bars, playback straight from a slot, trimming, a backup before every write, and a sweep of the macOS junk.
How is LooperCat different from rc5cat?
rc5cat is the same thing for the terminal: a CLI and a local web editor on the same knowledge base (shared golden fixtures). If a script suits you better, take it. LooperCat is a desktop app, and it has what a console never will: slot playback, waveforms, trimming, and control of the pedal's STORAGE mode.