Fidelia

Fidelia — Help

High-fidelity audio player for macOS and remote control for iOS. Bit-perfect playback with professional DSP, Audio Unit hosting, and headphone virtualization.

Contents

Getting Started

Library

The Library stores all your imported audio with metadata, artwork, and playlists. Files are referenced by location — Fidelia does not copy files into its library folder.

Importing Music

To audition tracks without adding them to your library — for example, listening to client mixes, evaluating new files before keeping them, or playing files from an external drive — see Preview Playlist.

Managing Your Library

Relocating Missing Tracks

If you move files to a new location, tracks will appear as offline (dimmed with a warning icon). Use File → Relocate Missing Tracks to point Fidelia at the new folder. It matches files by name and automatically updates all references.

Album View

The Library has two layouts, toggled by the List / Wall control in the window titlebar (next to Search). The song list is the default; the Wall is a graphical grid of your album covers. Whatever narrows the song list — a playlist selection, a search — narrows the Wall the same way.

Various-artist compilations group as one album — on the Wall and in the Sleeve — rather than scattering by track artist, and a real Album Artist always takes precedence over the compilation flag.

The Wall

The Sleeve

Opening an album lifts its cover into place on a full page, lit by a slow, breathing gradient drawn from the artwork and kept dark so it never glares. The Sleeve gathers the cover, album credits, and the album's tracks in order.

Editing Metadata

Open Get Info on a song with ⌘I or via the right-click menu. The dialog is fully editable for songs imported into Fidelia's library; songs sourced from Music.app are read-only (Music.app is the source of truth there).

Editable fields

Sample rate, bit depth, bitrate, duration, format, and file location are technical properties of the audio data itself and aren't editable from Get Info.

Apply to all songs in this album

At the bottom of the single-song dialog, the Apply to all songs in this album checkbox expands an edit to every song that shares the current Album and Album Artist. Useful for fixing genre or year across a whole album from one track.

Editing many songs at once

Select multiple songs in the library and open Get Info — a multi-song dialog appears with a subset of fields (Artist, Album, Album Artist, Composer, Genre, Year, Comment). Per-song fields like Title and Track number are hidden because their values aren't meaningfully shared across a selection.

What Save does

Clicking Save updates Fidelia's library database immediately, then mirrors the new values into the source file's embedded tags off-main:

For each format that supports it, Fidelia preserves frames and keys it doesn't manage itself — ReplayGain, MusicBrainz IDs, custom user tags from other editors all survive a Save.

Successful saves are silent. If a file write fails (volume offline, file became read-only, format unsupported), a transient toast appears at the top of the Library window confirming the database edit and explaining what didn't reach the file.

Library access for tag writes

For libraries on external volumes or NAS shares, Fidelia may ask once for folder access the first time you save tags into that location — granting the suggested folder covers every file underneath, persists across launches, and won't ask again for that library. Local libraries imported normally don't trigger any prompt.

Multi-song save progress

Album-scope and multi-song commits below 30 songs run silently in the background. Larger commits show a progress toast at the top of the Library window with a counter and Cancel button — you can dismiss the Get Info dialog while the writes finish. Cancel stops scheduling new writes; in-flight writes complete atomically (already-written files stay written).

If a file write fails: it retries automatically

When a tag write can't reach its file (NAS dropped, volume ejected, permission revoked), Fidelia queues the affected song and tries again on the next launch. Once the volume is reachable, the file gets the database's current values silently — no user action needed.

For the rare case where a queued retry can never succeed (a permanently-removed volume), File → Clear Pending Tag Writes empties the queue manually. The menu item is disabled when nothing is pending.

Playlist Folders

The sidebar supports nested folders for organizing large playlist collections. Folders are containers — they hold playlists and other folders, but never songs directly.

Creating folders

Organizing

Deleting

Right-click a folder and choose Delete Folder. Empty folders delete inline. Folders with playlists or sub-folders inside open a confirmation alert that lists what will be removed.

Music.app folders

With Music.app integration enabled, Fidelia mirrors the folder hierarchy from your Music.app library under the Music section of the sidebar. Music-side folders are read-only — they reflect Music.app's organization and update when Music.app changes.

Preview Playlist

The Preview Playlist is an opt-in scratch space for tracks you want to listen to without adding them to your Library. It's cleared automatically each time you launch Fidelia, so it never accumulates state between sessions.

Useful when you're auditioning client mixes, evaluating promo files before keeping them, or playing tracks from an external drive you don't want referenced in your permanent collection. Each new drop replaces the previous Preview session — Fidelia treats each batch as a new audition.

Turning it on

Open Settings → General → Library and enable Preview Playlist. A new Preview entry appears in the sidebar (under Fidelia, alongside Library) marked with a lightning-bolt icon to signal its ephemeral nature. The row is shown only while Preview has tracks in it; an empty Preview is hidden.

Adding tracks

⇧-drag works on Fidelia's own windows. Dropping on the Dock icon, using Open With → Fidelia from the Finder, or double-clicking an associated file always goes to your Library. For preview semantics from those entry points, see Preview-only mode below.

Each Preview drop replaces any tracks already in Preview — drop a list, the list plays from the first track. If a track in the new drop is also currently playing, it restarts from the beginning so the audition session is consistent.

Promoting tracks to your Library

Clearing

Preview clears itself at every cold launch — quit Fidelia and reopen it, and Preview starts empty. To clear during a session, right-click the Preview sidebar entry and choose Clear Preview.

Preview-only mode

If your primary use of Fidelia is auditioning rather than collecting — common for mix engineers, A&R, and reviewers — enable Send all incoming files to Preview by default in Settings → General → Library (visible once Preview Playlist is on).

With this mode on, every entry point — drag-and-drop, Open With → Fidelia, Dock-icon drops, and double-clicks — routes incoming files into Preview instead of your Library. Use File → Import to Library (⌘O) for the rare track you want to keep, or hold ⇧ while dragging onto a Fidelia window to import that specific drop.

Preview is a session-local, machine-local concept. It isn't synced via Music.app, never participates in playback history, and isn't visible to Fidelia Remote. Tracks that exist only in Preview disappear at next launch — back up anything you want to keep by promoting it to your Library first.

Internet Radio

Fidelia plays internet radio alongside the music you own. Stations live in their own Streams section in the sidebar, and every stream runs through the same reference engine as your local files — your output device, HeadSpace, and signal path, untouched.

Adding Stations

Playing a Stream

Station Presets

Presets are stations — nine numbered slots you recall blind, like the push buttons on a car radio. Right-click a station and choose Set as Preset to assign a slot (1–9); each slot holds a single station, so setting a slot takes it from whatever held it before. A preset station carries its slot number as a badge and leads the list in slot order — at the top when you're tuned to All, and at the top of its own band.

Recall any preset instantly with ⌃1⌃9, from Controls → Presets, or from the transport bank in Fidelia Remote — from anywhere in Fidelia, whatever you're doing.

The Tuner

Honest Fidelity

Streams are graded by their real source quality — the Fidelity Light and signal path read the stream's actual codec and bitrate, and never dress up a lossy feed as more than it is. Where a station broadcasts a lossless stream, you hear it lossless.

HLS, Opus, and Ogg Vorbis stations play natively. Streams are played, not stored — they aren't part of your on-disk library — and you can browse and play them from Fidelia Remote as well.

Playback

Click the track-time readout to change what it shows — including a precise volume level in dB — and Fidelia remembers your choice, the same way it remembers whether the timer counts up or down.

Fidelia can run as a clean file-to-DAC path or as a full DSP playback chain, depending on your Output, Audio Engine, HeadSpace, and Advanced settings. Bit-perfect mode bypasses the DSP chain entirely.

When you press pause with effects loaded (reverbs, delays, convolutions), Fidelia lets the plug-in tails decay naturally for up to a few seconds rather than cutting them off — same behavior a DAW would give you on a transport stop. Resume is still instant.

Now Playing

Now-Playing Panel

As you browse the Library, a now-playing panel stays in the sidebar with the current cover, a scrubber, and transport controls — playback is always to hand without switching back to the player window. Click the cover to jump straight to that album's Sleeve.

Fidelity Light

A small light beside the now-playing track shows at a glance how cleanly it's reaching your ears — a quick read on whether you're hearing the file untouched or with conversion and processing in the path. It's color-graded from a lossless, bit-accurate path through to a lossy source.

Click the light for the full signal path — every stage in order, from the source file through resampling, HeadSpace, Audio Unit effects, and dither to your output device, each one graded. Bit-perfect playback shows a short, clean path (source straight to output), because it bypasses the DSP chain entirely.

Player Views

Audio Output

Fidelia sends audio to your selected output device using its own playback engine. Configure device selection, hardware sample rate, and routing in Settings → Output.

Bit-Perfect & Exclusive Mode

These options live in Settings → Advanced and control how Fidelia interacts with the output hardware and DSP chain.

DSD Playback

Fidelia plays DSD files (.dsf and .dff) directly — no conversion, no orphaned files. By default the 1-bit DSD stream is decoded to high-resolution PCM in real time, so DSD plays gaplessly on any output device and rides the same signal path — and the same SRC settings — as the rest of your library.

Bit-Perfect DSD over PCM (DoP)

For DACs that decode DSD natively, Settings → Output → Play DSD bit-perfect (DoP) sends the untouched DSD bitstream to the DAC inside a standard PCM carrier (the DoP standard). Enable it per device.

Sample Rate Conversion (SRC)

When the source file's sample rate does not match the active device rate, Fidelia applies sample rate conversion from the Settings → Audio Engine tab.

Dither

When reducing effective bit depth, Fidelia applies dither from the Settings → Audio Engine tab to preserve low-level detail.

HeadSpace

HeadSpace is Fidelia's headphone virtualization DSP. It simulates the spatial characteristics of loudspeaker listening through headphones, reducing fatigue and creating a natural soundstage. Configure it in Settings → HeadSpace.

Crossfeed

Equalization

Per-Band Crossfeed

Monitoring

HeadSpace is designed for headphone listening only. Disable it when using speakers.

Audio Units

Fidelia hosts Audio Unit (AU) plug-ins in the playback DSP chain. Add EQ, reverb, metering, and other compatible Audio Unit effects for real-time processing.

Opening a slot is instant: your plug-ins appear at once while Fidelia scans them quietly in the background. A slow or unresponsive plug-in won't hold up the list — each is given a moment to respond, then set aside if it doesn't, and stepped around the next time you open the picker, so the slot stays responsive even with a large or misbehaving collection.

Editor Window

When you open a plug-in's editor, Fidelia adds a thin bar at the top of the window with:

Editor windows open at each plug-in's natural size. Resizing, where supported, is handled by the plug-in itself inside its view.

Plugin Hosting

Fidelia hosts Audio Unit plug-ins either in-process (loaded directly into Fidelia's own memory, lowest latency, matches Logic Pro and Fidelia 1.x) or out-of-process (routed through macOS's AUHostingServiceXPC sandbox, slightly higher latency, but isolated from Fidelia). The choice is made per slot — manage it in Settings → Plugins.

Per-Slot Hosting Preference

Each slot has a three-way picker:

Settings → Plugins

The Plugins pane shows a row per effect slot with:

PACE / iLok-Protected Plug-ins

Plug-ins from Moog, Strymon, UAD, UADx, and other PACE- or iLok-protected vendors need special runtime privileges to load in-process. With Auto (the default), Fidelia's pre-flight scanner detects these plug-ins and routes them straight to out-of-process hosting on first load — no authorization dialogs appear.

If you set a slot to Force In-Process and load a PACE-protected plug-in into it, macOS may present one or more one-time authorization dialogs (for example, a Lower Security Settings dialog or a PACE licensing alert). These are macOS / PACE prompts, not Fidelia errors. Approving them unlocks the plug-in and the dialogs won't appear again for that plug-in.

Hosting preference is per slot, not per plug-in. If you swap a different plug-in into a slot, the new plug-in inherits the slot's setting. For most users, leaving every slot on Auto is the right choice — Fidelia's scanner handles PACE-protected plug-ins correctly without user intervention.

Switching a Loaded Plug-in's Mode

Format Conversion

Right-click songs in the library and choose Convert Format… to convert between formats.

Metadata (title, artist, album, artwork, etc.) is preserved in converted FLAC and M4A files. WAV and AIFF output does not include metadata. To edit metadata after import, see Editing Metadata.

DSD & APE

DSD — DSF and DSDIFF (.dsf, .dff) play directly, decoded to PCM in real time by the engine. Nothing is converted on import and no extra files are written next to your originals. To keep a permanent PCM copy, use Convert Format… to export to ALAC or FLAC.

Monkey's Audio (.ape) is converted to Apple Lossless on import; the converted file plays natively and the original is kept alongside.

Tags are read from each source file — DSF via its embedded ID3v2 chunk, APE via the APEv2 footer. (DSDIFF tag chunks aren't read yet, so a .dff without external tags falls back to its filename.)

Fidelia Remote (iOS)

Control Fidelia from your iPhone or iPad over your local network. The free companion app shows your library, now playing info, and full transport controls.

Music.app Integration

Enable Music.app integration in Settings → General to browse your Apple Music library directly in Fidelia. Songs, playlists, and artwork are imported read-only.

Keyboard Shortcuts

Play / PauseSpace
Next Track⌘→
Previous Track⌘←
Seek Back / Forward⌥⌘← / ⌥⌘→
Volume Up / Down (0.5 dB)⌥⌘↑ / ⌥⌘↓
Recall Station Preset 1–9⌃1⌃9
Import to Library⌘O
Add to Preview Playlist⇧⌘O
Toggle Library⌘L
Toggle Mini Player⇧⌘M
Player On Top⇧⌘T
Large / Medium / Small / Smaller⌘1⌘4
DIM⇧⌘D
Mute⌘M
Find Artwork Online⌥⌘A
Get Info (selected song[s])⌘I

All shortcuts are customizable in Settings → Commands.

Supported Formats

Troubleshooting

Contact Support

Questions, feedback, or bug reports — reach us at support@audiofile.engineering