The ES9018K2M DAC chip features three digital filters that subtly alter the sonic presentation and pre-ringing artifacts of digital signals:
Try using a different USB port on your computer (preferably a USB 2.0 port instead of USB 3.0). Ensure the cable is pushed firmly into the unit's rear panel. If the issue persists, download and install standard Virtual COM Port (VCP) drivers for Windows. The Audio Drops Out After the Update
The internal software on the standard 6000A consists of microcode that governs: The ESS Sabre32 ES9018K2M DAC digital filters.
(requiring "GVR" firmware). Flashing the wrong version can cause persistent settings errors. File Placement : The firmware file (typically a file) must be placed in the root directory of the USB drive, not inside any folders. Execution Procedure
The VFD display will flash a sequence of numbers. For example: