Review on 🔌 Enhance Your Audio/Video/Electronics with iFi iPower X Low Noise Power Supply DC Adapter (5V) by Joseph Reed

I use the ifI iPower X as an external power supply for my ifI Zen dac V2 and I have found that it really improves my Zen dac. I can tell the difference in sound clarity, stage, dynamic range, bass performance and fine detail in audio components. I'm just a little confused on how the iPower X works. It looks like my Zen DAC is using both power supplies while it's running. However, the DAC does not remove power from USB B when iPower X is connected to it. I'm not sure if this is how it's supposed to work. Another thing I don't like is that there aren't enough instructions or illustrations, especially for important and risky tasks ie. What is the polarity of the external power connector, positive in the middle or outside.