The UI is called the Quill Interface. It is monochromatic, text-based, and lightning fast.
This is a love-it-or-hate-it design. For purists, it replicates the Zen of a CD player. For modern users expecting Spotify Connect, it will feel archaic.
Battery Life: Because there is no power-hungry Android OS or Wi-Fi chip, the 19 QSP delivers 19 hours of playback on single-ended and 14 hours on balanced. This beats the Sony Walkman NW-ZX707 by nearly 7 hours.
The star of the show is the audio architecture. Sonnix abandoned the popular ESS Sabre chips for the AKM AK4493SEQ x 4. 19 qsp player by sonnix
The 19 QSP is not an Android player. This is a significant choice. Sonnix opted for a proprietary RTOS (Real-Time Operating System) based on Linux. Why? To eliminate Android's audio latency and resampling issues. You cannot stream Spotify or Apple Music natively. You must load FLAC, WAV, DSD (up to DSD512), or MQA files onto a microSD card (supports up to 2TB).
At the heart of the Sonnox Oxford EQ is a sophisticated filter section that goes beyond standard parametric EQ. Most digital EQs offer bandwidth (Q) controls, but the Sonnox Oxford EQ features Quadratic Sidechain Processing.
In simple terms, QSP allows the plugin to maintain a natural, analog-style curve even when the user performs extreme boosts or cuts. The UI is called the Quill Interface
The Problem with Standard EQ: On many standard EQ plugins, if you use a very narrow Q (high bandwidth) to notch out a frequency, the shape of the curve can become asymmetrical or create phase artifacts that make the audio sound unnatural or "phasy."
The Sonnox QSP Solution: The QSP engine ensures that the filter shape remains constant and musical regardless of the bandwidth setting. This results in:
How does the 19 QSP stack up?
| Feature | 19 QSP by Sonnix | Fiio M11S | Shanling M3 Ultra | Hiby R6 III | | :--- | :--- | :--- | :--- | :--- | | Price | $649 | $499 | $399 | $549 | | DAC Configuration | 4x AK4493SEQ (Quad) | 2x CS43198 | 2x AK4493SEQ | 2x ES9038Q2M | | OS | Sonnix RTOS | Android 10 | Android 10 | Android 12 | | Streaming | No | Yes | Yes | Yes | | Battery Life | 19 Hours | 14 Hours | 12 Hours | 11 Hours | | Output Power (Bal) | 690mW | 560mW | 260mW | 440mW |
Verdict: If you use Tidal/Qobuz offline mode or own a local FLAC library, the 19 QSP wins on sound quality. If you need YouTube Music, look elsewhere.
