Since purchasing my new Samsung Galaxy S9 Plus I have been trying to find a suitable mobile DAC/amp that will work with it to a reasonable degree. The main issue, which many folk have documented in various places on here, is that devices with USB-C ports will often attempt to charge DAC/amps, which drains the device battery. There are various solutions documented that normally involve ordering USB-C to micro-B cables with OTG. There is also mention of changing USB mode for the USB connection once it is made. My own experience is that results are hit-and-miss. I tried a multitude of cables and adapters to connect to my Oppo HA-2 with no success and I ended up selling it on. At home, I have successfully connected my phone to my Oppo HA-1 by using a USB-C hub with power delivery connected to a charger, and with a normal AB cable connected from the hub to the HA-1. This is sufficient to convince the S9 that it should not be doing any charging but obviously it is not very portable. Specific devices may deal with OTG and charging better than others. I have been assured by Chord support staff that the Mojo works with the Samsung Galaxy S8 and that the S8 will do the right thing if "music device" is selected for the USB connection. However this option is not available in the pulldown list on the S9. I imagine other devices and OS combinations will have mixed results. I thought I would start a thread where we could list what definitely works, what definitely doesn't, feedback from vendors and support etc. I hope this is not presumptuous - maybe I am the only one having major problems.