Fred, There is a whole host of possible missteps. It's why I sent him the link to my JRiver tutororials for DSD. Likely he will report back after that.
Bebp86, DoP is a vehicle for sending DSF and DFF files to a DAC that doesn't have custom ASIO drivers (wherever that DSD came from, whether originally DSD or converted PCM-to-DSD). It is simply a (now ubiquitous) clever workaround so DAC manufacturers didn't have to roll their own DSD drivers. The fact that you want JRiver to convert PCM to DSD is one thing. You need to set that in JRIver in the DSP window (also knowing your correct driver setting). Then he needs to pick the correct signal path for his DAC (i.e audio device driver) and he needs to set bitstream to DSD, etc. It's all in my tutorials.
Do the Lampis use DoP (I forget) or do they have custom ASIO drivers for direct raw DSD? If DoP do Lampi owners choose WASAPi mostly? Once I know that I could spell this out in screenshots if that helps.