DAC Noise: Causes and Fixes by Type

Identify the Type of Noise

DAC noise comes in several distinct forms, each with different causes and solutions. Start by determining which type you’re dealing with.

White Noise (Hiss)

A constant “hiss” that’s audible even with no signal playing.

Common causes:

• High noise floor in the DAC’s amplifier section
• Using high-sensitivity IEMs
• Gain set too high

Fixes:

• Switch to Low gain
• Use an attenuator like the iFi iEMatch when driving sensitive IEMs
• Use the DAC’s line output into a separate amp instead of its headphone output

Hum (Buzz)

A persistent low-frequency “hum,” typically at 50 Hz or 60 Hz.

Common causes:

• Ground loop
• Power supply issues
• Interference from nearby power adapters or monitors

Fixes:

• Try a USB isolator (e.g., iFi iDefender+) if connected via USB
• Plug the DAC and PC/monitor into separate power strips
• Use a 3-prong to 2-prong adapter to break the ground loop (exercise caution with safety)
• Attach a ferrite core to the USB cable

Pops and Clicks

Irregular “pop” or “click” sounds during playback.

Common causes:

• USB transfer errors
• Driver issues
• Poor handling of sample rate switching
• Low-quality USB cable

Fixes:

• Try a different USB cable
• Switch to a different USB port (rear panel ports are more stable than front panel)
• Update the DAC’s drivers to the latest version
• Lock the sample rate in your OS audio settings
• Adjust the USB buffer size (Windows)

Digital Noise (Whine / Buzz)

High-frequency “whine” or “buzz” sounds.

Common causes:

• Noisy USB power
• EMI (electromagnetic interference) from inside the PC
• Using a cheap USB hub

Fixes:

• Use a self-powered USB hub
• Add a USB power filter (e.g., iFi iPurifier3)
• Switch to optical (Toslink) to electrically isolate the DAC from the PC

Fundamental Solutions

If the fixes above don’t resolve the issue, consider the following:

• Optical connection: Completely isolates the DAC from the PC electrically, eliminating all USB-borne noise
• External power supply: Switch to a DAC that uses an AC adapter rather than USB bus power
• DDC (Digital-to-Digital Converter): Improves USB receiver quality

Conclusion

Accurately identifying the type of noise is the first step toward a fix. In most cases, swapping cables, changing USB ports, or eliminating ground loops will resolve the problem.