1-bit · Features

Every feature, on one page.

What 1-bit does, grouped by what you would want from it. On a wired DAC the audio path is bit-exact by default; anything that changes the sound is a choice you make, and Signal Path says so.

Get 1-bit on the App Store ↗ What arrived when

91 features in 15 groups. Everything here is in 1-bit 2.1, the version on the App Store, and works with the current bridge; a line that needs a bridge, is off until you switch it on, or is still in beta says so.

Bit-exact, and the proof

The bits in your files are the bits that reach your DAC.

On a wired USB DAC, with everything at its defaults, nothing in the path changes the audio. The rest of this group is how the app shows you that, rather than asking you to take it on trust.

No mixer, no resampling: PCM goes straight to the output at the file’s own sample rate, bypassing the iOS mixer; the hardware rate is renegotiated for every track, and the render thread is lock-free — no syscalls in the audio callback. What “bit-exact” means →
DSD as DoP: DSF and DFF files are wrapped in DoP frames and handed to the DAC untouched — DSD64, DSD128 and DSD256 — so if your DAC shows DoP lock, you are hearing the original 1-bit stream. DoP vs native DSD →
Signal Path: Open it on any track to follow the signal from source to decoder, engine, session and output, each stage reporting what it did — and the bit-exact seal appears only when nothing alters the bits: not the volume as it is right now, not an effect, not a conversion.
Labelled, never hidden: Converted DSD, a bridge-optimised copy over Bluetooth or AirPlay, crossfeed, spatial audio, ReplayGain, DSD-domain processing: whatever changes the sound is written on the screen as a stage in the diagram or a card naming the reason.
DAC Diagnostics: The detected DAC, the resync timing in force, live session facts, a counter of clipped samples, and a rate sweep that probes which PCM and DoP carrier rates your DAC actually accepts.
Live audio meters Off by default: An Analyzer tab in Signal Path — a real-time spectrum, left and right peak bars, true peak, dynamic range, bandwidth, and estimated key and tempo — fed by a read-only tap at the decoder output; with the switch off, no tap exists at all.
Track analysis Needs a bridge: Tracks your bridge has analysed carry a measured true peak, a dynamic-range score, key and tempo, a FLAC checksum test that flags a file altered since it was encoded, and a reading of where a “hi-res” file’s content really stops. File provenance →
DAC profiles: A curated resync delay and DSD ceiling for the DACs we have measured — Chord, iFi, FiiO, Topping, Mytek and more — and a “for your DAC” card in Settings → Audio naming the settings it was tuned for; it advises and never changes anything. DAC compatibility →
Profile my DAC: A guided wizard runs the measurements the built-in profiles came from — which rates lock, whether DSD64, 128 and 256 lock over DoP, how long the DAC takes to settle — and ends in an email with a paste-ready profile, so your DAC can be supported properly.

DSD

Every DSD file you are likely to own.

DSF, DFF, compressed DFF and SACD rips, up to DSD256 — and when there is no DAC in the path, DSD still plays and says what happened to it.

DSF and DFF, DSD64 to DSD256: DSD256 over DoP works on hardware that supports it; whether it does is a question about your DAC’s USB descriptors, not about the phone. Do higher DSD rates matter? →
DST-compressed DSDIFF: Compressed .dff files decode as they play, gaplessly, at DSD64 and DSD128. .dsf vs .dff vs SACD ISO →
SACD ISO rips: An .iso opens into ordinary per-track rows with the disc’s own track names, which play, download and sit in playlists like any other track — the stereo area, at DSD64.
DSD on any output: On AirPods, AirPlay, CarPlay, the speaker, or a DAC that refuses the rate, DSD plays anyway, converted to PCM on the phone and labelled as converted wherever the signal is described; a capable wired DAC still gets the untouched DoP path.
Conversion, your way: When needed, Always, or Never; “Play DSD as PCM on this DAC” for the one DAC whose DSP mode turns DoP into noise; and a conversion level from +6 dB, the SACD reference, down to 0 dB, one step at a time.
Converted ahead of time Needs a bridge: Your bridge can render a DSD file to PCM once — compact for CarPlay and wireless, faithful for a wired DAC that cannot take the file’s rate — so the phone streams a fraction of the size; a rendition never substitutes for DoP, and the original is one tap away. Renditions →
Pre-cache by default, streaming by choice: The whole file is cached before play so the marker stream cannot underrun mid-track; “Stream large DSD files” trades that for faster starts on a reliable local link.
Gapless DSD: Seamless between DSD tracks when the rate matches, with the DoP marker phase preserved across the boundary.

PCM and formats

Native rate, every format.

The lossless and lossy formats most libraries hold, played at the file’s own sample rate and bit depth.

FLAC, ALAC, WAV, AIFF, MP3, AAC: Played at the file’s own sample rate, up to whatever your DAC accepts; Signal Path reads a FLAC’s real bit depth rather than the decoder’s working format, and does not vouch for a 32-bit file the path cannot carry exactly.
Gapless: Seamless between tracks when the format matches — over a local share or a remote bridge, where the next track is fetched early enough, timed by the connection’s measured speed.
Big files start sooner Off by default: Large FLAC, WAV and AIFF files from a bridge or a share start once the download is safely ahead of playback; if it falls behind, the player pauses on Buffering and resumes exactly where it stopped, so silence is never passed off as music.
Tags read in full: Title, artist, album artist, composer, conductor, work, performer credits, multi-value artists, the compilation flag, dates and embedded artwork — from ID3, Vorbis, MP4, DFF, WAV and AIFF.
Format badges: Every row and Now Playing carry the codec, sample rate and bit depth, and a WAV holding a compressed format is labelled lossy rather than hi-res.

Sources

Where your music lives.

Five kinds of source, in any combination, all scanned into one library — and a demo library for anyone who has none yet.

SMB share: Point the app at a NAS or a Mac with File Sharing on — SMB2 or higher — scan, listen; nearby servers show up by Bonjour, and the password lives in the iOS Keychain.
1-bit bridge: A free companion server for Mac, Windows, Linux, Raspberry Pi or Docker, with its source public: a pre-built manifest syncs a large library in seconds, it is reachable over Tailscale, and TLS fingerprint pinning means only the bridge you paired with can serve you. About the bridge →
1-bit Cloud Beta: The same bridge, run by us on a machine in Switzerland: sign in with Apple, add music from any computer through your library’s web page, and it appears in Sources like any other bridge — 20 GB free, every file downloadable back bit-exact, and one step deletes the lot. What it stores →
UPnP / DLNA media servers: Browse and play straight from a NAS media server or a Chord 2Go’s own library, with no bridge in the path.
A folder on the device: Pick any folder on the iPhone or iPad, in iCloud Drive or on a USB-C drive, and 1-bit plays the files where they are — no copying, no new permission — while copying music into the app’s own folder still works too.
A demo library, in one tap: No server yet? Add Demo Bridge pairs a small read-only library so you can try browsing, playback, waveforms and the analyzer before setting anything up.
Pairing that fits the moment: Approve the device on the bridge’s console with a six-digit code, scan a QR code, open a bridge:// link that carries a one-time code, or tap a bridge found on the network.
Cellular, per source: Always allow, Warn before streaming, or Wi-Fi only — the same gate covers the next-track preloader and honours Low Power Mode.

Library and browsing

A library, not a file browser.

Albums, artists and the rest, built from the tags you already have and kept in the order you choose.

Eight ways in: Albums, Artists, Playlists, Favorites, Composers, Genres, a flat Tracks list and Folders — from every source, in one library.
Your order, your layout: Choose how each list is sorted and laid out in Settings → Library → Browsing; artist pages open on the newest album, and sorting albums by year adds a year index along the edge.
Composers and Genres: Read from the tags you already have, tuned for classical name forms and multi-genre fields; nothing is written back to your files, and both work in search.
Credits and Appears On: Guest and session appearances show on an artist’s page, a “Conducted by” header tops a conductor-consistent album, and a long-press on a shared credit opens the featured artist.
A tidier Artists list: Artists who appear only on compilations stay out of the list until you ask for them, and a compilation with no album artist files under Various Artists.
Search: Albums, artists, tracks, composers, genres and playlists — and Settings is searchable too.
Scans that respect your time: Rescans skip unchanged folders, a big first scan resumes in the background while the device charges on Wi-Fi, and renamed or moved files keep their identity, hearts and playlist slots.
Artwork and artist images: Covers from your files and your bridge; optionally, and off by default, artist photos from Deezer and, per bridge, Atlas for higher-resolution art, artist biographies and album descriptions. Atlas →
Album booklets Needs a bridge: On albums your bridge holds a PDF booklet for, a badge on the artwork opens the liner notes full-screen. Booklets →

Now Playing

Built to be looked at, not just heard.

A full-screen player with the lyrics, the waveform and the facts about the signal, on iPhone and iPad.

A light design and a dark one: Colours drawn from the cover, the secondary controls folded into one tray, and a theme that follows iOS or your own pick.
Lyrics: Tap the artwork and it becomes the lyric sheet: synced lyrics follow line by line, and word by word where the file carries word timing — from the file’s own tags, a sidecar beside it, your bridge, or an online source you switch on yourself — with a timing nudge for files whose sync is a little off.
The waveform scrubber: The track’s own waveform drifts behind the timeline, computed by your bridge or drawn on the device when the source has none, DSD included — never on the audio path.
Queue, shuffle, repeat: Play Next and Add to Queue from the long-press menus, an Up Next list, shuffle and repeat, and a sleep timer.
Favorites: Heart a track or an album from the row, the long-press menu, the mini player or the Now Playing header, and everything you heart collects in the library’s Favorites section.
What is reaching the DAC: A format badge for the file and a live readout of the sample rate the DAC is receiving, on the screen while you listen.
A floating player: Optional on iPhone — a compact pill that expands into a full player without leaving the tab — and on iPad a single bar with the scrubber inline, whose deck adds an Up Next column.
More room to scroll: The standard tab bar shrinks while you scroll, with the mini player beside it, and comes back when you scroll up.
On iPad: The whole library — mixes, favorites, the analyzer, Signal Path — lays out for the width it has.

Controls everywhere

Transport that works where you do.

The Lock Screen, Control Center, widgets, AirPods, Apple Watch and Siri — and the app stays honest about what it is doing while your attention is elsewhere.

Lock Screen, Control Center, AirPods, Apple Watch: Play, pause and skip from any of them; on iOS 27 they run on Apple’s new Now Playing session, with shuffle, repeat and the Favorite heart included.
Home Screen widgets: What is playing, with full transport controls, on the Home Screen.
Siri: “Play [album, artist, playlist or genre] on 1-bit” — at home, on the Lock Screen and in CarPlay; Apple handles the voice, and the app receives only the resolved request.
Background audio: Playback survives screen-off and app-switch, and an interruption from another app’s audio resumes with sound, the timer where the music is.
A DAC that comes and goes: Unplug the DAC and playback pauses instead of jumping to the speaker; plug one in while a DSD track is loading and it plays as DoP.

CarPlay

A real CarPlay app.

The library you scanned on your phone, on the head unit — with the same honesty about DSD.

Browse, search, tap to play: Library, Now Playing, search, recent searches and recently played on the head unit, with an Up Next list.
Downloads in the car: Downloaded albums have their own list, so a drive through a dead zone keeps playing; on iOS 27 the app moves straight past tracks it cannot reach instead of stalling on each one.
Dependable transport: Steering-wheel pause and resume keep your position, and a silent stall heals itself.
DSD in the car: The CarPlay browser lists PCM; a DSD track started from the phone plays converted to PCM, and Signal Path says so.
Drive Mix and car-sized files Needs a bridge: A bridge builds a Drive Mix from what you play in the car and can serve CarPlay-sized copies, so a 192 kHz master is not streamed to a head unit that cannot use it. Variants →

Casting

Play to a Chord 2Go, or any DLNA renderer.

The renderer fetches the audio itself, bit-exact, over your LAN.

From your bridge Needs a bridge: Pick the renderer from the Now Playing output picker and it fetches the audio straight from your bridge over the LAN; generic renderers work as well as the 2Go. How to set it up →
From a UPnP server: A track from a UPnP media server plays on a renderer that fetches it straight from that server — 2Go to 2Go works.
Honest about what cannot be cast: SMB and on-device tracks have no address a renderer could fetch from, so casting is offered for bridge and UPnP sources only.

Downloads and offline

Your music, with no network.

Downloads you choose, caches you switch on, and a player that keeps going when a source is out of reach.

Offline downloads: Tap the download icon on a track or an album; the files go to app-private storage — hidden from the Files app, excluded from iCloud backup, and removed when you delete the download or the source.
Offline keeps playing: When a source is out of reach, playback skips to the next track you have instead of stopping.
Prefetch, and an overnight cache Off by default: Fetch the next few tracks in your queue ahead of time, or cache your Home mixes while the device charges on Wi-Fi — never on cellular, and the cache can never evict a download you chose.
Download state you can trust: What is shown as downloaded is reconciled against what is really on the device at every launch, and a file that already lives on the phone counts as available offline.

Playlists, favorites, history

Yours, backed up to a server you control.

Everything here stays on your device unless you switch on a backup — and then it goes to your own bridge, never to us.

Playlists: Build them from any source — one playlist can mix tracks from a bridge, a share and the device — and play, queue or append from a long-press.
Playlist files: Drop .m3u or .m3u8 files onto an SMB share or an on-device folder and the next scan imports them as read-only playlists that follow the file — absolute or relative paths, UTF-8 or Windows-1252.
Playlist backup Off by defaultNeeds a bridge: Your playlists survive a reinstall and reach every device paired with the same bridge; two devices editing at once converge, last writer wins. How it works →
Favorites backup Off by defaultNeeds a bridge: Your hearts follow you to your other devices and feed a Favorites mix on Home; the first time you enable it against a bridge that already holds favorites, the two lists are merged, not overwritten.
Listening history Off by defaultNeeds a bridge: What you played, for how long, in what format and on which output — stored on your bridge, shown on its console, exportable as JSON or CSV, and never sent anywhere else.
Smart Mixes on Home Needs a bridge: Heavy Rotation, On Repeat, Drive Mix, Wind Down, Lift Off, an Auto Mix sequenced by musical key, a time-of-day mix and more, rebuilt daily by your own bridge from the history you chose to share. The twelve families →
Export: Everything you made on a bridge — playlists, favorites, history — as one file from its console; 1-bit Cloud has the same button, and every music file is downloadable back.

Sound shaping, all optional

Off by default. On when you say so.

The direct path is the default. Each of these inserts a stage that Signal Path shows, and the bit-exact seal steps aside while it is in.

ReplayGain: Track or album mode on PCM, from the file’s own tags, while DSD always stays bit-exact; on iOS 27, files on the device with no loudness tag get an on-device estimate so they can be levelled too.
Crossfeed: First-order Bauer crossfeed for headphones and Bluetooth, bypassed on USB DACs and on DSD so the direct path stays intact.
Spatial audio Beta: A binaural renderer that opens the stereo image out around your head, with head tracking on AirPods that report it, stage width, room reflections and a focused-centre option — PCM only, and DSD is never touched.
DSD-domain processing: A volume stage, decimator and modulator that work in the DSD domain rather than converting to PCM first; it alters the bits, so Signal Path reports it as engaged.
Upscaled copies Off by defaultNeeds a bridge: A wand on an eligible track switches between the original and an upscaled PCM copy your bridge made offline; the original is never replaced and stays one tap away. Upscale variants →

Diagnostics

When something is off, the facts are on the device.

Logs, thermals and the health of your bridge, readable in the app and sent nowhere.

Logs that stay on the phone: A rolling diagnostic log in Settings that never leaves the device unless you attach it to a support email yourself.
Thermal and battery: A read-only dashboard of the device’s thermal state now, a twelve-hour timeline, and which parts of the app back off as a result.
Bridge health Needs a bridge: A paired bridge’s counters show in Diagnostics, so you can see whether it is healthy without opening its console.
Crash and performance reports: Collected through Apple’s MetricKit, kept on the device, and never uploaded.
iOS 27, with a switch: Settings → iOS 27 shows the status of each feature that uses the new OS, and one switch reverts every iOS 27 path at once; everything keeps working on iOS 26.1.
Listening Tips: A guide inside the app on what makes it sound right — the DAC, the settings, and what each optional stage does to the signal.

Accessibility

Made for VoiceOver, large text and less motion.

The system settings you rely on are honoured throughout the app.

VoiceOver: Rows, cards and controls carry labels and values, section headings are in the rotor, and a transport button that is disabled says why.
Dynamic Type: Type follows your text size, and controls keep a 44-point target as the glyphs grow.
Reduce Motion: With Reduce Motion on, the waveform holds still and the press animations and cross-fades are dropped; motion also stops while paused and when the device is warm or in Low Power Mode.

Privacy

Nothing to collect.

No account unless you choose the cloud, no analytics, and traffic that goes to servers you control.

No account, unless you choose the cloud: No analytics, no ads, no tracking, no SDKs that phone home; 1-bit Cloud is the one feature that needs an account, and it says what it stores before you sign in.
Credentials stay on the device: SMB passwords and bridge tokens live in the iOS Keychain.
Your servers, your traffic: Playback talks to your share, your UPnP server and your bridge; the three optional lookups that reach a third party — artist images, Atlas metadata, online lyrics — are off by default and named in the policy.
Pinned, and reviewed: Only the bridge you paired with can serve you — a rotated certificate means re-pairing, by design — and the app and the bridge have been through an outside security review.
The policy: Line by line, including what 1-bit Cloud holds. Privacy policy →

Free on the App Store

Bring your library to your DAC.

No subscription and nothing to buy in the app. The bridge is free with its source public, and 1-bit Cloud includes 20 GB. Setup and FAQ live on the support page.

Free · iOS 26.1+ · iPhone & iPad