I'm happy only for the streaming and preamp. DAC for me is not satisfying in resolving. Sounds narrow and confused. Headphone amp is useless. So I connected the Wiim to an external DAC (loxjie d40 pro) and things are changed. Resolved the dac/headphone problems. The DAC is connected via XLR to a Fosi za3. I used the sub out of fosi instead of Wiim one. Someone has complained Fosi has a 100hz sub fiter, but for me is a perfect cut. The room correction doesn't fit my room. Maybe too wide. Any measurement produce horrible shapes. Bottom line for me a good streamer, but you can save money buying wiim pro and a nice dac
The DAC in the Ultra measures great and there is nothing wrong with the headphone amp. It is easily able to drive a Sennheiser HD800S and a Hifiman Stealth Arya Magnet.