If you need smooth,GDA-600 from Adcom might be the ticket. The GDA-600 came out in 1994 (I believe) and was Stereophile Class C. It has input for S/PDIF over RCA/coax and toslink plastic. It has has an aes/ebu input, if that matters. Smooth sounding, and not bad since you can find these for $200 used on the street.
You might see a GDA-700, but all it really adds over the 600 AFAIK, is HDCD. Both units can handle 20bit/44.1k. It also has a detactable IEC. Unfortunately the unit is quite large (footprint). So I doubt it is very portable, if that is part of your requirements.
FWIW, I used a GDA-600 until I switched it for an EVS Millennium DAC I.
You might see a GDA-700, but all it really adds over the 600 AFAIK, is HDCD. Both units can handle 20bit/44.1k. It also has a detactable IEC. Unfortunately the unit is quite large (footprint). So I doubt it is very portable, if that is part of your requirements.
FWIW, I used a GDA-600 until I switched it for an EVS Millennium DAC I.