30 dB is a lot. I don't have one but I would be sure that there is a problem. What DAC are you using and what type digital interconnect?
Does your IFi Zen Steam have Low Gain?
Any IFI Zen Stream owners notice a very low gain on this streamer? Mine has approximately 30db+ lower gain than other input devices. Not sure if mine has an issue or this is its normal performance. I tried reaching out to iFi on line support and their response was “thank you for notifying us we will pass it on to our development team for future enhancement consideration”.