Meringo: USB DAC Music Player

A music player for people who treat listening as a ritual, not a feed.

Built for FiiO M21 owners and Jellyfin/Subsonic self-hosters who want a player that refuses to lie about the signal path. If you primarily stream from Spotify, Tidal, or Qobuz, Meringo isn't for you — no native integration with commercial streaming, by design.

Meringo plays your high-fidelity local library alongside your Jellyfin or Subsonic server, with an audio engine that never touches the bits unless it has to. Every screen is built for slow listening. Every diagnostic tells you what your gear is actually doing.

THE BIT-PERFECT PATH
Direct-to-DAC routing on supported hardware, including full FiiO SDK integration on the M21. AAudio low-latency on phones with capable DACs. The Now Playing format strip tells you exactly what path your audio is taking — and lights an amber warning the moment AudioFlinger resamples or truncates the signal. Transient modifiers (ReplayGain, crossfade, concurrent audio) decorate the badge as suffixes — never as silent lies.

IN THE CAR
Android Auto with working voice — ask for an artist or an album, or just "play some music," and it plays from your library. Tap a track and its whole list follows.

TWO LENSES — VAULT & CLOUD
Browse your on-device music files side-by-side with your Jellyfin or Subsonic collection. Cross-source twin detection — MBID, ISRC, and Chromaprint fingerprint — collapses the same recording across local and cloud into a single library entry. Cloud failures fall back to the Vault copy automatically; a Wi-Fi blip never stalls playback.

SONIC MATCH & SONIC RADIO
Tap the wave icon on Now Playing and Meringo finds tracks in your library that genuinely sound like the one playing — same harmonic shape, same rhythmic feel. Tap a match to seed Sonic Radio: an auto-extending five-track texture chain. No external recommender, no telemetry.

THE WORKBENCH
A 10-band parametric EQ in double-precision biquad math with TPDF dither at every integer-PCM output stage. Two preset slots (A and B) you can flip between mid-track to compare two calibrations against each other — or against the raw signal — without rebuilding either curve. Pink noise and sine sweep test signals route through your live EQ for headphone calibration. A headroom reserve pre-attenuates so boosts never clip. The Tuning Vault stores personal calibrations and ships a Community Profiles collection (AutoEQ-format import via file picker or clipboard paste).

ATMOSPHERES — MOOD BY SOUND
Library navigation by what tracks actually sound like, not by genre tags. Five mood classes — Lite Roast, Fruity, Medium Roast, Dark & Bold, Slow Drip — computed deterministically from Chromaprint fingerprints, technical metadata, and MusicBrainz signals. The same file always gets the same mood. Tempo cross-filter (Slow / Mid / Fast).

THE ACOUSTIC DNA
Every album surfaces its real codec, sample rate, bit depth, and source. A three-tier Dynamic Range Index — Ultra, High, Standard — gives you the audiophile shortlist at a glance.

SMART & MOOD PLAYLISTS
Rule-based playlists continuously rebuilt from your library: Hi-Res Vault, Deep Cuts, plus custom rules combining source, codec, bitrate, year, genre, mood, and recency.

ARTIST BIOGRAPHIES
Tap any artist on Now Playing for a bio from Wikipedia and MusicBrainz.

PRIVACY BY DEFAULT
Meringo is local-first. Music metadata, encrypted server credentials, preferences, and cached artwork stay on your device. Audio fingerprinting happens entirely on-device — Sonic Match and twin detection compute their signatures locally and never send one anywhere. MusicBrainz, the Cover Art Archive, and Wikipedia are queried for editorial enrichment. Optional ListenBrainz scrobbling and Sentry crash reporting are off by default, consent-prompted on first run. Nothing tracked, nothing sold, no account required.

Built in Erie County, NY · support@meringo.app · The Field Guide inside Settings is a chapter-book manual to the engine.