I use the GeerFAB and it sounds incredible with a great DAC. Even with an average DAC the SACDs are well worth the listen via the GeerFAB. There is a cheaper Chinese alternative that is touted on here. I am not interested in that since the $600 GeerFAB sounds great and is an American product.
I use a $150 used OPPS BD???. You need to take the HDMI from the OPPO to the GeerFAB. Then take SPDIF from the GeerFAB to you DAC.
The important consideration is that the DAC needs to support DSD over PCM (DoP), I just checked the Buchardt Powered web site, and it seems that this is a wireless connection and a SPDIF could not be connected to the MASTER speaker (not sure if that concept even exists here).

