Hello Daniel,
I read the REW-Basics document on Github in which a spdif-cable is used to connect the Laptop with the Hifiberry Board. My laptop has no SPDIF Output, nor do I own an audio interface with a SPDIF Output.
So I wonder, if there is another way to connect my Win10 Laptop with the REW Software to the RPi 3B+/Hifiberry Dac+ DSP board to do measurements?