From analysis of well-behaved CX31993 designs (e.g., certain JCALLY, Avani dongles), the following layout fixes are effective:
To properly “fix hot” for the CX31993, the manufacturer should publish a thermal design appendix including:
Until then, engineers must rely on empirical testing and community-derived fixes. Consumers should be aware that a “hot” CX31993 dongle is not necessarily defective, but may have a thermally insufficient design.
Sources (summary):
End of report
The CX31993 (often branded by Conexant or Synaptics) is a popular budget USB-C DAC chip known for high-resolution audio (32-bit/384kHz) but frequently lacks an official, public datasheet. Users often report "hot" operating temperatures or overheating, especially when paired with an external amplifier like the MAX97220.
Below is a guide addressing the technical specifications and common "hot" fixes for this chip. CX31993 Core Specifications
Since an official datasheet is hard to find, technical communities rely on these verified parameters: Sampling Rate: 32-bit / 384kHz SNR (Signal-to-Noise Ratio): >128dB DNR (Dynamic Range): >120dB THD+N: 0.0003% (-95dB) Output Power: 65mW (dual channel) Amplifier Class: Class G Why it Gets "Hot" (Common Causes)
The Real Issue with the Spark (CX31993 + MAX97220) : r/iemlndia
is a popular, budget-friendly USB-C DAC chip found in many "noname" and branded dongles like the Audiocular CX Pro
and JCally models. While it offers high-resolution audio (32-bit/384kHz), it is frequently reported to run hot, especially when paired with a MAX97220 amplifier chip or used with a PC. Why the CX31993 Gets Hot High Power Draw:
The combination of the DAC and an additional amplifier chip (like the MAX97220) pulls significant power to drive headphones, often up to 2 volts. Form Factor:
These dongles are extremely small, leaving very little surface area to dissipate the heat generated by the chips. PC Power Delivery:
Users often report higher temperatures when connected to a PC compared to a phone, likely due to the PC's more robust (and sometimes noisier) USB power supply. Top Fixes for Overheating and Noise
If your CX31993 dongle is becoming uncomfortably hot or producing static, try these common community-vetted solutions: Is it normal for a May DAC to run hot? - Facebook
Conexant CX31993 is a widely utilized, high-performance Class G audio DAC (Digital-to-Analog Converter) chip often integrated into affordable USB-C dongles. While praised for its 32-bit/384kHz sampling rate and neutral sound signature, some users experience overheating issues, which can lead to audio artifacts like static or hiss. Understanding the Overheating Problem
is designed for low power consumption, but high-intensity use—such as high-fidelity audio playback on PCs or driving demanding IEMs—can cause the small chip to dissipate significant heat.
Symptoms: The USB-C connector or dongle body feels hot to the touch, often followed by a gradual buildup of static noise or a sudden disconnect. Primary Causes:
Inappropriate Buffer Settings: Small audio buffer sizes on PCs or Android apps (like UAPP) can force the chip to process data too rapidly, increasing thermal load.
Power Management: Some devices may provide unstable or excessive voltage to the USB port, pushing the chip beyond its standard operating parameters.
Physical Constraints: The ultra-compact aluminum shells of these dongles often lack sufficient surface area for heat dissipation. Practical Fixes for Overheating
-based device is running hot, several software and hardware adjustments can mitigate the issue: cx31993 datasheet fix hot
Adjust Audio Buffer Size: In dedicated audio apps like USB Audio Player Pro (UAPP), navigate to settings and increase the buffer size. This reduces the processing frequency, which can lower the chip's temperature.
Toggle Bit-Perfect Mode: Temporarily disabling "Bit-perfect" mode may help if the source device is struggling to manage high-resolution streams, though this may slightly impact sound quality.
Use a USB 2.0 Port: If using the dongle on a PC, try a USB 2.0 port instead of USB 3.0/3.1. Some users find that the lower power delivery of USB 2.0 helps the chip run cooler.
Hardware Reinforcement: For DIY enthusiasts, adding a small piece of heat shrink tubing or a metal pen spring around the cable base can help distribute heat and prevent internal wire fatigue, which often contributes to "dying" units. Technical Specifications (Reference)
According to the limited available technical data and community reviews from platforms like Head-Fi: SNR: >128dB Dynamic Range: >120dB Output Power: ~65mW @ 32Ω Decoding: Up to 32bits/384KHz Despite its small size, the
is a "class G" amplifier, which is more efficient than standard Class AB but can still reach high temperatures if not properly ventilated or if software settings are too aggressive. Conexant (CX-Pro) CX31993 USB-C Amp/DAC Review
The Conexant CX31993 is a high-performance USB-C DAC (Digital-to-Analog Converter) chip favored by audiophiles for its impressive 32-bit/384kHz sampling rate and low cost. However, its compact design can lead to heat management issues, especially when paired with an external amplifier like the MAX97220 or when driving high-impedance headphones. CX31993 Core Specifications
According to various technical summaries, the chip delivers top-tier performance for its size: Sampling Rate: 32-bit / 384kHz (PCM) Signal-to-Noise Ratio (SNR): >128dB Dynamic Range (DNR): >120dB Total Harmonic Distortion (THD+N): 0.0003% (-95dB)
Output Power: Typically 65mW (often limited by the specific dongle's power supply). Why Your CX31993 DAC Gets "Hot"
Heat in these dongles usually stems from high power draw or poor thermal dissipation in the enclosure:
The CX31993 DAC chip is a common budget-friendly component often paired with the MAX97220 amplifier in portable USB-C dongles. While a formal, public "datasheet" from the manufacturer (Conexant/Synaptics) is notoriously difficult to find, community documentation and real-world testing highlight a recurring issue where these devices run excessively hot and produce static. Why it gets "Hot"
Power Overdraw: The chip often struggles with power management when connected to USB 2.0 ports or devices, leading to heat accumulation.
Implementation Flaws: Budget designs may lack proper heat dissipation (heatsinks or thermal pads), causing the zinc alloy or plastic shells to become hot to the touch during extended use.
High-Resolution Stress: Playing high-bitrate files like DSD can push the DAC to temperatures around The "Fix" (Community-Sourced)
Since there is no official firmware "patch" for a hardware thermal issue, users rely on these practical workarounds:
Software Tweaks (UAPP): 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.
Physical Modification: Applying small VRM heatsinks and thermal pads to the internal PCBA has been shown to drop operating temperatures from to roughly
Port Selection: Use USB 3.0 (or higher) ports when possible. Testing suggests the chip runs "super cool" on USB 3.0 devices compared to USB 2.0, where it may struggle to "suck in" power efficiently.
Static/Hiss Resolution: If the heat is accompanied by a loud static build-up, immediate unplugging is recommended, as this typically indicates a temporary hardware "lock-up" or thermal throttling. Technical Specs (Inferred) Decoding Up to 32-bit / 384kHz Amplifier Class G (often integrated or paired with MAX97220) SNR Reported around 128dB (chip spec, implementation varies) Power Consumption
Low (ideally), but increases significantly under load/USB 2.0
Are you seeing this heat issue primarily when using it with a PC or a smartphone, and are you getting any static noise along with the temperature rise? Audio Expansion Card - CX31993 Datasheet From analysis of well-behaved CX31993 designs (e
Reports indicate that the Conexant CX31993 (often paired with the MAX97220 amplifier chip) can experience overheating issues, particularly when used with PC USB ports or during prolonged high-power output. Summary of Reported Heating Issues
Thermal Behavior: While many standard CX31993 implementations run cool, units paired with a MAX97220 op-amp for higher power output (up to 125mW) are more prone to heating up.
Symptoms: Users have reported the USB-C connector becoming hot to the touch, often followed by static, hiss, or audio cutting off. Primary Causes:
Improper Power Handling: Excessive heat can occur when the DAC draws more power than the internal thermal management can dissipate, especially on desktop PC ports that may lack strict current limiting.
Internal Shorts: Rapid overheating immediately upon connection often points to a defective unit or a internal short circuit. Recommended Fixes & Workarounds
If your CX31993-based device is running hot or exhibiting noise, reviewers and users suggest the following: Software Tuning (Mobile):
Increase Buffer Size: In apps like USB Audio Player PRO (UAPP), increasing the buffer size can reduce the processing load and potentially lower thermal stress.
Disable Bit-Perfect Mode: Temporarily turning off bit-perfect mode may stabilize performance if the hardware is struggling with high-resolution streams. Hardware Stabilization:
Grounding Check: If using a PC, ensure the system is properly grounded, as grounding issues can cause static that accompanies the heating.
Sequence of Connection: Try plugging your headphones into the DAC first, then connecting the DAC to the device to ensure proper initialization. Alternative Recommendations:
For users requiring consistent reliability without heating, high-quality alternatives like the Apple USB-C Dongle (A1749) or DACs using the CS43131 chip are often recommended for their superior power efficiency. Technical Specifications (Datasheet Summary) Conexant (CX-Pro) CX31993 USB-C Amp/DAC Review
🛠️ Troubleshooting: CX31993 DAC "Running Hot" & Data Shortage CX31993-based dongle
(like the Abigail, CX-Pro, or JCally JM6) is heating up or behaving poorly, you aren't alone. Here is the breakdown of why this happens and how to handle it. 1. The "Heat" Problem: Why it Happens Power Mismatch: Users have reported that the CX31993 (often paired with a
amplifier) can get physically hot, especially when plugged into a PC USB port rather than a phone. Current Draw:
In some implementations, the DAC draws more power than its tiny chassis can dissipate, leading to thermal buildup and eventual static or hissing noise Device Issues:
Overheating is sometimes linked to using the DAC with high-sensitivity IEMs at high volumes or using poor-quality USB cables. 2. Immediate Fixes & Workarounds Increase Buffer Size:
If the heat is causing crackling or distortion, try increasing the USB Buffer Size in apps like USB Audio Player PRO HiBy Music Disable Bit-Perfect: Some users find that toggling Bit-perfect mode
off temporarily stabilizes the device when it begins to heat up. Driver Reset:
On Windows, if the device isn't recognized or runs hot while failing to play audio, manually uninstall the generic USB driver in Device Manager and let Windows reinstall it fresh.
Ensure the dongle is in a well-ventilated area; avoid leaving it tucked under a laptop or in a pocket while in use. 3. The "Datasheet" Mystery Finding an official datasheet for the
is notoriously difficult as Conexant (now part of Synaptics) often keeps these documents private. Confirmed Specs: amplifier chip. Technical Limitation: Until then, engineers must rely on empirical testing
Because it’s an integrated budget chip, it may exhibit electrical noise above 20kHz, which can contribute to minor thermal overhead during complex decoding.
Are you experiencing this on a specific device (phone vs. PC) or with a specific set of IEMs? Any link to the cx31993 datasheet? - Facebook
Where to find the ic datasheet and pinout details for SN8P2612? * Kisur Chandro Das ► Repair, Restore or Scrap it Audio and Video. ChiFi Audio Reviews Audio Expansion Card - CX31993 Datasheet
The Conexant CX31993 (often branded under Synaptics or as "CX-Pro") is the undisputed king of ultra-budget USB-C audio DACs. Originally designed as a highly integrated, low-power audio codec for mobile devices, it gained legendary status in the audiophile community when implemented in dirt-cheap $5 to $15 dongles. It directly rivals (and in some areas outperforms) the famous Apple Dongle. 📊 Technical Specifications A look at the raw hardware capabilities of the chip: Max Sampling Rate: PCM 32-bit / 384 kHz.
SNR (Signal-to-Noise Ratio): Exceeds 128 dB in optimal setups. DNR (Dynamic Range): Over 120 dB. THD+N: 0.0003% (-95 dB).
Output Voltage/Power: ~1V output, producing roughly 65mW @ 32Ω (nearly double the output of a standard US Apple dongle). ⚡ The Good: Why It's a "Giant Killer"
🔥 Exceptional Clarity and TonalityUnlike many cheap DACs that sound muddy or warm, the CX31993 is famous for its lean, neutral, and highly transparent sound signature. It handles treble beautifully, creating an open, airy soundstage with clean instrument separation.
🔌 Perfect Power for AndroidThe Apple USB-C Dongle is hardware-limited to 0.5V on Android devices without special third-party apps. The CX31993 has no such restriction. It will natively push its full 1V power on Android, Windows, and Mac, giving your In-Ear Monitors (IEMs) the juice they actually need.
🔇 Pitch-Black Noise FloorEven with extremely sensitive multi-driver IEMs, the background hiss on this chip is practically non-existent. It is exceptionally quiet.
🔋 Extremely Low Power DrawThis chip runs remarkably cool and sips very little battery from your smartphone, making it ideal for daily commuting. ⚠️ The Bad: The Caveats
🛑 Not for Demanding HeadphonesWhile 65mW is fantastic for IEMs and standard consumer headphones, the standalone CX31993 lacks the raw current and voltage to properly drive hard-to-power equipment. High-impedance headphones (like 150Ω or 300Ω Beyerdynamics) or low-sensitivity planar magnetic headphones will sound thin, bass-shy, and flat.
🔍 "Implementation Lottery" and Build QualityBecause the CX31993 chip is so inexpensive, dozens of random white-label factories on platforms like AliExpress buy the chip and build their own dongles.
Many budget options leave the gorgeous 8-core silver-plated copper wire naked without a protective plastic sleeve.
These exposed wires are notoriously prone to fraying or snapping if shoved into tight pockets. 💡 Pro-Tips for Buying a CX31993 DAC
The "Dual-Chip" Upgrade: If you plan on driving bigger headphones, look specifically for dongles labeled "CX31993 + MAX97220". These units pair the CX31993 DAC chip with a Maxim MAX97220 standalone amplifier chip. This raises the power output to about 125mW–140mW, successfully bridging the gap for harder-to-drive gear.
Stick to Trusted Brands: To avoid getting a unit that falls apart or has poor internal soldering, buy your CX31993 dongle from recognized budget audio brands such as JCALLY (e.g., the JM6 or JM7 lines), Abigail, or GraveAudio. JCALLY JM6E CX31993 DAC - Reviews - Head-Fi
The Conexant is a widely utilized high-fidelity USB-C DAC chip found in many "audiophile" dongles for its impressive 32-bit/384kHz sampling rate and >128dB SNR. However, users frequently report that these devices can run "hot" during extended use, particularly when driving high-impedance headphones or decoding DSD files. Why the CX31993 Runs Hot Heat in these ultra-compact dongles is typically caused by:
Not every hot CX31993 is broken. The datasheet allows for junction temperatures up to 125°C. If your device meets the following, the heat is normal:
Also, do not attempt to fix the chip if your dongle is a known good design (e.g., AudioQuest DragonFly Cobalt uses a similar but different chip). Always verify the actual component marking – some "CX31993" clones have different thermal characteristics.
Do this if VBUS > 4.2V. Remove any existing shunt resistor or cheap linear "regulator."
Components:
Procedure: