Three main factors can cause this and there are three possible countermeasures:

■When the Windows built-in sound device setting is the cause

See case 4 in the troubleshooting guide [here].

■When the connection or other equipment is the cause

An unstable connection with your PC/Mac might cause this problem.

To solve this, shut down your PC/Mac and disconnect all other USB devices and USB hubs. Then, connect the OPUS-QUAD directly to a different USB port.

■When your system (PC/Mac) is the cause

Doing the following might solve the issue:

- Quit all other applications.

- Disconnect from the internet and exit security software.

- Turn off wireless connections such as Wi-Fi or Bluetooth.

- Turn off power-saving settings.

If your computer's system doesn’t meet the requirements of rekordbox, it might cause an issue. See details on system requirements [rekordbox.com].