@silverfoxvtx1800 - I really had no issue with the Tambaqui and I could certainly understand why so many enjoy it in their systems. I perceived it as being super clean but not bright or etched. It displayed good power and good extension in the high frequencies while providing well-defined, impactful bass. Comparatively, my NOS R2R DACs seem more expressive in the midrange frequencies, more full-sounding but just as powerful in the low frequencies, and provide a bit more tonal color and body, IMO. If somebody said those NOS DACs are not as strictly faithful to the source, I wouldn’t argue as I suspect the Tambaqui is very faithful to the source. Unfortunately, I did not own the ultraDigital at the same time I had the Tambaqui and so I was unable to feed it through its I2S input, which I was told by a dealer is superior to the other inputs (just their opinion).
@mintakax - Ultimately, I decided to stick with the Mojo Audio NOS R2R DACs that I already owned - the Mystique EVO Pro (mine had the special AD1862Z chips) and the Mystique X SE NCZ (designating nano-crystalline chokes and 1862Z chips). I later added a Merason DAC1 MkII, which was also a very nice sounding DAC and smooth/refined but slightly less enjoyable to me than my Mojo Audio DACs. At this time, I still have the Mystique X SE NCZ, but have sold the EVO PRO and the Merason, and I have been pondering where I might go from here while still sticking with NOS R2R topology DACs (i.e., totaldac, MSB, CAD 1543, others?).
You can read my thoughts about comparisons between several DACs in this thread.