Quick answer
A USB ground loop isolator breaks the electrical ground loop between your computer and audio gear, removing the hum and buzz caused by multiple ground points. If your audio has a low-frequency hum that stops when you unplug the USB cable, this device is the direct fix.
Why a ground loop happens
When your computer and audio interface or DAC are plugged into different wall outlets, they can have slightly different ground potentials. That difference creates a ground loop, which manifests as a steady hum or buzz in your audio signal.
The problem is common in home studios and desktop setups where multiple devices share power strips or wall outlets. It's not a sign of faulty gear—it's an electrical issue that a ground loop isolator can solve.
Isolator vs. other fixes
A USB ground loop isolator targets the specific path between your computer and audio device. It's often simpler and more effective than trying to rewire your power setup or using a power conditioner, which may not address the ground loop directly.
However, if your hum persists after using an isolator, the cause might be elsewhere—like a faulty cable or a noisy power supply. In that case, you'll need to look beyond the USB connection.
Diagnose and fix your audio hum
- Symptom: You hear a continuous low-frequency hum or buzz in your audio, especially when your computer and audio gear are plugged into different outlets.
- Likely cause: A ground loop created by multiple ground points in your audio chain—typically between the computer's USB port and the audio device's ground.
- Corrective action: Insert a USB ground loop isolator (like the iFi Audio iDefender+) between your computer and the USB audio device. This breaks the ground loop and eliminates the hum. After installing, listen for the hum. If it's gone, you're done.
- When to stop or choose another option: If the hum persists after using the isolator, the issue may be a faulty USB cable, a noisy power supply, or a problem inside the audio device itself. Stop troubleshooting the ground loop and test those components instead. Consider replacing cables or testing the device on another computer before buying more gear.
Product spotlight
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iFi Audio iDefender+: The iFi Audio iDefender+ breaks the ground loop by interrupting the USB ground connection, preventing the hum and buzz caused by multiple earth points. It's a simple plug-and-play solution that fits between your computer and USB audio gear, so you don't need to rewire your setup.
iFi Audio iDefender+
