Right now though I don't think the ASIO driver works as well as the WASPI, it doesn't like large buffer sizes and the volume knob on the E5 does'nt do anything. So WASPI is recommended. Ok but after I figured out all that, so far so good with using it as a DAC for a PC.
One major concern is that on my Android phone the E5 also charges the battery. This in my opinion is not necessary and just waste battery power, and might even add noise. I like the idea on the Fiio E18 to leave charging as optional.
I use foobar WASAPI event for E5, works well so far.
Yes, agree, charging of mobile phone should be made optional.