@Mr. Electric Wizard :
I'll try to provide some info regarding audio in
Windows, and how I see things. I am happy to be corrected if I am wrong though, so you may want to look out for replies to my post.
ASIO was developed Steinberg, but is widespread among good audio devices [*1]. It allows stereo and multi-channel I/O on devices which support those, in this case 2-channel output. It locks the device to the player meaning that no other players can access the audio device whilst it is in use. The ASIO driver normally provides faster response and buffer control and so lower latency for recording interfaces, which doesn't matter here.
WASAPI is built into Windows 7 and later. There are two modes of operation, Exclusive and Shared. Exclusive mode allows the hardware to be locked to a software program, and this behaviour is very similar to ASIO. It is also relatively quick for recording devices, but I think ASIO is usually faster with less glitches. Shared mode allows for two audio devices to be accessible at the same time, say a recording device and a different playback device. Not relevant to us here, but I think WASAPI Shared can cause issues with clock sync and therefor recommend to use Exclusive mode where possible.
Additionally WASAPI has two modes that are sometimes exposed in the playback software, these are Event and Push (sometimes slightly differently named). In a nutshell Event means the device requests audio data packets from the player, whereas the other mode means the player just pushes the data out and the device has to handle it. These minor modes are the same for both Exclusive and Shared. It is more complicated than that when synchrous and asynchrous USB is thrown in, but generally speaking Event (device request data) is preferred, as is Exclusive mode.
Both ASIO and WASAPI support PCM, but WASAPI does not support DSD natively. DSD over PCM (DoP) is supported by both because they only see PCM data (the DSD is losslessly packaged within). A dedicated ASIO driver will allow for native DSD to stream to a DSD DAC.
[*1] there are some good hardware devices that do not have ASIO drivers, but mostly, it is the cheaper and less good devices that don't have ASIO drivers. Maybe my opinion here, but I think it's a sensible thing to offer.
I had to install the Topping drive on a Windows 7 netbook because the D10 just didn't seem to work properly on it. That said, there were a few pops and clicks on playback with that machine, which hasn't happened on others, so I'll put that down to the netbook computer more than anything.
The good news is that installing the Topping drive is quick and easy. There is a tray icon that allows for volume control (of the DAC chip) as well as ASIO buffer settings, not that they matter too much here, it's not a recording interface and thus latency is not an issue to consider. The tray icon can be removed by closing it. There is a startup shortcut in the start>startup folder, so removing that stops the tray icon appearing. Nice, easy, I like that.