I have appreciated your impressions and evaluations on this thread. It was not clear to me if you utilized the Tambaqui with a preamp or direct. I have the Mola Mola Makua preamp with DAC (Tambaqui card). I have read that several Tambaqui owners have preferred preamp in their systems over Tambaqui direct. The Makua DAC does not have an I2S output as does the stand alone Tambaqui, and I have not listened to the stand alone Tambaqui. I have AES/EBU from my Antipodes K50 G4 to the Makua as well as RJ45 ethernet. I have another unit taking USB from the K50 G4, but have been using USB output from Lumin X1 to the Makua. While I enjoy all the inputs to the Makua, I favor the USB slightly over the AES/EBU and both over ethernet, but far too many variables in my system, including player hardware, player software, and cabling manufactures and models to generalize for others. Of note, I also use Daedalus DID isolation devices under my Makua rather than the default support rails.
Thank you again for the significant time you have invested in these comparisons.