A fantastic little piece of hardware
Like many others, I'm pairing this Topping D10 DAC with an O2 Headphone amplifier wired to a pair of HD6XX from Massdrop. I'm using Foobar2000 in Windows 10, with the proper drivers from Topping (that you have to download yourself), including the ASIO driver (replacing basic WASAPI) and the direct DSD link. You can look at the photos from Jcog below, I've got exactly the same audio devices.
The result is phenomenal. Seriously.
I used to have an ODAC (same designer as the O2 amp, it's a ~$100 DAC meant to be "transparent", i.e. perfect to the human ear in A to D conversionm and rivals reference hardware costing 10X more), but that ODAC died last year. I thought it good to save a few bucks on this D10 rather than buying a new ODAC, and with the added samplerates (192) and native DSD compatibility, it seemed like a great deal, provided the DAC part performed well. I can attest to that, I'm not missing my ODAC at all. This D10 is a wonderful piece of hardware.
The dual output (RCA + Digital S/PDIF or coax) is great to have both headphones and some hi-fi connected to it — sound exits both at all times, so you just have to mute any non-used device. Obviously, via digital output the DAC will not be used in the D10, but the signal transport is very good, no jitter, just a great output.
Other than that, not much to say, it does the job and does it well.
Update 2020-03-23: still working great! I'm now using it mostly with Linux; works out of the box. I haven't tried DSD yet (I need a player on the Linux side and haven't investigated yet for a good candidate). This D10 is wonderful.
Would recommend to a friend.