…passively dampens the electrical treble resonance. The chip’s 2Vrms output drives them cleanly, and the headphones’ own impedance profile smooths the hot region without external parts.
Because Conexant’s assets changed hands over the years (eventually landing under Synaptics ), an official public-facing datasheet can be incredibly elusive. Most implementation details must be reverse-engineered or gathered from manufacturer reference designs.
If using USB Audio Player Pro , increasing the USB Buffer Size and toggling Bit-Perfect mode can sometimes stabilize the power draw and reduce crackling/static associated with heat. cx31993 datasheet fix hot
The CX31993 requires a 1.8V digital core and a 3.3V analog supply. Most dongles use a cheap LDO (Low Dropout Regulator) to step down USB’s 5V to these voltages. If the LDO is inefficient (e.g., a 1117 clone), it burns off 1.7V as pure heat before the power even reaches the DAC. This is the primary culprit.
By applying the , performing the Thermal Pad Mod , or simply buying an impedance adapter, you can continue enjoying 384kHz playback without burning your fingertips. …passively dampens the electrical treble resonance
Measure voltage between VBUS (pin 1) and GND (pin 10). Also measure VDD_CORE (pin 11) if accessible.
According to user reviews, the CX31993 running warm is . The chip is designed to operate within a specific thermal range, and the metal casing acts as a heat sink. However, if the dongle is hot to the point of being uncomfortable or causing audio distortions, the "hot fix" steps (specifically using an impedance adapter or ensuring low-power idle) should be applied. Most dongles use a cheap LDO (Low Dropout
Many budget options leave the gorgeous 8-core silver-plated copper wire naked without a protective plastic sleeve.
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.