Cx31993 Datasheet Fix Better Link →
The datasheet specifies a wide operating voltage, but the internal charge pump requires clean decoupling. The chip shares its digital power line (V_BUS) with the analog power amplifier section. Without external filtering, high-frequency USB switching noise leaks into the audio path, causing an audible hiss. Common Faults and How to Fix Them
If you are looking to improve or fix a CX31993-based device, consider these community findings: Noise Filtering : Developers at the Framework Community
| Feature | Conexant CX31993 | Realtek ALC5686 | | :--- | :--- | :--- | | | Up to 32-bit/384kHz | Up to 32-bit/384kHz | | Signal-to-Noise Ratio (SNR) | >128dB (DAC) / 124dB (DAC+HP) | ~124dB | | Distortion (THD+N) | 0.0003% (-112dB) | Not widely published | | Key Strengths | Objectively superior specs, great for general reliability and "transparent" sound | Subjective "musical" sound profile, but may cause relay/popping noise on some devices | | Target Audience | Users who want measurable, distortion-free performance | Users who prefer a warmer, "analog-like" sound signature | cx31993 datasheet fix better
After reverse-engineering several dongles and consulting application notes, here’s how to in the CX31993 datasheet for better performance and reliability.
A properly fixed CX31993 beats the Apple dongle for high-res listening because the Apple dongle is hardware-capped to 48kHz on Android/Windows unless you use expensive apps. The datasheet specifies a wide operating voltage, but
have noted high-frequency noise (>200kHz) in some implementations. Since it is a Class G amp, adding a low-pass filter to the output can help clean up ultrasonic artifacts that may interfere with sensitive equipment like oscilloscopes. External Amplification
By default, Android, Windows, and macOS resample all audio to a unified rate (usually 48kHz). This software resampling degrades the audio quality. Common Faults and How to Fix Them If
This is perhaps the single most-reported problem with CX31993 dongles, particularly when the dongle is connected to a PC with an AMD GPU or a gaming motherboard.
Enable Developer Options and disable "Disable USB audio routing." Use USB Audio Player Pro (UAPP) for bypassing Android's internal SRC (Sample Rate Conversion). Fix C: "Muddy" Sound or Lack of Bass
Despite the stellar specs, real-world performance varies wildly depending on the product's (PCB design, soldering quality, shielding) and the host device (phone, PC, Raspberry Pi).
Under the tab, change the Default Format dropdown to 32-bit, 384000 Hz (Studio Quality) or 24-bit, 192000 Hz (recommended for best system stability).