I can’t say for Mac but on most PCs there is an option in the BIOS to power down completely when shutdown. This is normally not enabled because people usually expect the USB ports to be powered even while shutdown for charging etc.
On my desktop PC with an MSI motherboard, this feature is called “ERP Ready”. I have enabled this and so my system completely shuts down. All USB ports and Ethernet are powered down.
It’s not the IFI Zen DAC. It’s your Desktop PC/Laptop that is keeping it by supplying power to the USB ports even after shutting down. There’s no way for the Zen DAC to know this unless IFI’s driver for the PC can send a command to the device to shutdown when the PC is shutting down.
Here’s how you can test this easily.
1. Try connecting your phone to the same USB port after shutting down and see if it still charges.
2. If you have an Ethernet port on the PC, connect your router’s Ethernet via cable to the PC and you’ll see that the Ethernet light stays on even after shutting down.
On my desktop PC with an MSI motherboard, this feature is called “ERP Ready”. I have enabled this and so my system completely shuts down. All USB ports and Ethernet are powered down.
It’s not the IFI Zen DAC. It’s your Desktop PC/Laptop that is keeping it by supplying power to the USB ports even after shutting down. There’s no way for the Zen DAC to know this unless IFI’s driver for the PC can send a command to the device to shutdown when the PC is shutting down.
Here’s how you can test this easily.
1. Try connecting your phone to the same USB port after shutting down and see if it still charges.
2. If you have an Ethernet port on the PC, connect your router’s Ethernet via cable to the PC and you’ll see that the Ethernet light stays on even after shutting down.