Hi friend, As introduction from Fiio, the M6 produce Hi-res quality of sound. So, do we need to use any portable DAC in combination with M6? I have a Senn HD 598 headphone, what portable DAC should I combine with M6? Is that when using with DAC the quality of sound better? Please share...

Dear friends, I purchased Fiio M6 today. It's impressive by quality of music. I can install Spotify via apk format and it works well. I also enjoy listening to Online Radio News such as BBC, CNN, Fox, therefore I have tried to install TuneIn App via apk format on my Fiio M6, but I can't...