Check the signal path, including input and output connections, for any signs of damage, oxidation, or poor contact.
The CX31993 can deliver amazing 32bit/384kHz audio without burning your desk – but only if you respect the thermal laws hidden in its elusive datasheet. cx31993 datasheet fix hot
After applying the 75Ω adapter to a generic CX31993 dongle and measuring with a calibrated microphone (and subjective listening on Moondrop Blessing 2), the following changes occur: Check the signal path, including input and output
If you are driving 16-ohm IEMs at high volume (30mW output), the chip might draw 90mW from USB. The 30mW difference is heat. But the "fix hot" issue arises when idle current jumps to 300mW due to a design flaw—leading to 200mW of waste heat inside a tiny 5g metal dongle. The 30mW difference is heat
The Conexant CX31993 has become ubiquitous as a budget-friendly USB-C to 3.5mm DAC dongle. Its subjective reputation, however, is polarized: many praise its detail retrieval, while others complain it sounds “hot,” “glassy,” or “fatiguing.” This harshness is not a flaw in the core DAC architecture—it is a predictable consequence of and missing post-DAC filtering , as hinted at in the component’s reference design.