First off, I apologize if this has been covered before, I did a little search but nothing detailed and I couldn't find anything specific to this. I thought I'd just jot down my own experience of running ASIO from a HTPC(or any Windows PC for that matter) to a USB DAC and getting sources like Spotify to get bit-perfect sound output and bypass Windows downmixing tracks to a lesser quality. I'm not an audiophile, I don't generally know the in depth technical science behind it all, I just make my own judgments on whether something sounds better or not. I've tried both WASAPI and ASIO, and to me ASIO sounds far better. Assuming your DAC USB driver and the ASIO4ALL driver are both installed, usually you can use a specific program like foobar to select ASIO4ALL as the output device, and from the ASIO4ALL control panel your DAC should appear as a device. For me, this was fine for when I was I playing very few of my high-bit rate FLAC files, but to be honest most of my listening is done through Spotify. Spotify has no native way to select the output audio device in Windows and I searched for a while looking for alternatives, I tried a program called Fidelify, which for me was too buggy and it looks like development has ceased. I then came across VB-Audio Virtual Cable, this seemed to answer all my prayers. It's act's a virtual sound device in Windows and adds an ASIO Bridge and outputs to your USB DAC. So with this installed, I now get constant ASIO bit-perfect sound from what application I use, I no longer have to manually run all my audio through foobar, I have Spotify and iTunes running ASIO perfectly As I said, this is just rough notes on what I did, if there is interest for a guide(if it hasn't been done before already), I'll happily update the post with screenshots and steps once I've got some spare time.