Your Chord dac needs to see 5v on your USB cable. You can provide a clean noise free 5 volts using this Elijah Audio
Isolate BL cable and included Musical Paradise MPU1 battery supply.
Unlike a cell phone battery, the MP-U1 uses high end voltage regulators to provide a clean and quiet 5 volts.
The 30cm cable (micro-usb) is hand made from Mundorf cable and covered in cotton.
The batteries in the MPU1 have been replaced recently providing years of no hassle use.
Selling because I now only use a Poly with my Mojo.
The best upgrade you can make (if using a computer as a source) for your Chord.