The Conexant CX31993 is a high-performance USB-C DAC/Amp chip widely used in ultra-portable dongles (often branded as "CX-Pro" or "Abigail"). While it is praised for its high sampling rate and low cost, users often seek "fixes" for issues like high-frequency harshness or low driving power for demanding headphones. These specs are standard across most CX31993-based devices: Resolution: Up to 32-bit / 384kHz PCM. Signal-to-Noise Ratio (SNR): >128dB. Dynamic Range (DNR): >120dB.
Some batches enumerate as “Conexant USB Audio” without a unique PID/VID. cx31993 datasheet fix better
Pin 1: HP_OUT_L Pin 2: HP_OUT_R Pin 3: AGND Pin 4: VDD (3.3V) Pin 5: USB_DP Pin 6: USB_DN Pin 7: DGND Pin 8: VDDIO (1.8V) The Conexant CX31993 is a high-performance USB-C DAC/Amp
| Register | Function | Useful values | |----------|----------|----------------| | 0x03 | HP amp gain | 0x00 = -6dB, 0x02 = 0dB, 0x03 = +6dB | | 0x06 | Mixer control | Bit 3 = HP enable | | 0x0A | LED/GPIO | 0x01 = LED on | | 0x10 | PLL config | Default 0x88 for 44.1/48kHz | Signal-to-Noise Ratio (SNR): >128dB