I lived some time without that DAC and sleep mode was ok. Last night I connected it and found its light on during "sleep". Then I changed sleep mode to hibernation (25) and got zero battery.
I made some measurements and discovered that DAC's consumption is about 1 watt. I don't think it can eat all battery. It seems like USB activity doesn't allow to sleep.
The 00s are gone. People just want to close and open their lids.
Another surprise is the DAC (2 watts consumption btw) being connected to the left USB makes all system hot and less hot to the right USB. This is MAC, ladies and gentlmen! 😎
What is the condition of your battery?
Go to your System Information, then the Power tab.
You also may want to consider connecting your power adapter when using the DAC--particularly when your battery may be starting to show its age.
The 00s are gone. People just want to close and open their lids.
Another surprise is the DAC (2 watts consumption btw) being connected to the left USB makes all system hot and less hot to the right USB. This is MAC, ladies and gentlmen! 😎
Apple or Apple Fans will spin that as a feature. If you are in a cold setting, plug in on the left. If in a hot setting, plug in on the right. Only Apple genius can anticipate environmental scenarios and engineer such an elegant solution. 😉