I’ve just installed this DAC a few hours ago and am very impressed at how it sounds.
I’m using it in my office system like this:
Ethernet from a Airport express Ethernet port > RasPi B + DAC > SMSL SA amp > Teufel speakers
In the Volumio UI, I chose the “Hifiberry” I2S settings. Some other setting I tried didn’t work.
Note this DAC is not plug and play with the B+ RasPi. Better get a B version so it can be connected directly into the P5 header (solder the 8 pin header first) in order to keep the I2S connections as short as possible.