dac 20bits with SCD1 16bits output as transport?

OK people,correct me about:I have a scd-1 as transport with a Cello reference dac,that use UV22 super cd encoding processing,fully feature 20 bits high resolution(as specs described).I found in my sistem(JRDG Concentra 2+ Apogee Duetta Signature)a radical upgrade with this dac over my scd-1 in both(sacd & regular cd ways)when using good recordings,specialty with XRCD`s or HDCD`s.The output signal of the scd-1 is 16 bits as transport.The dac features sample rates (32k,44.1k or 48k) & resolution (16 or high),but no matter I use 20 bits recordindgs is glued in (44.1k & 16).Today I tried using a Arcam FMJ CD23(24/96)as a transport too,and was the same.After compared sounds of both, the Cello kept his place with a huge diference too.I`m really happy how is sounding,but still interested of what I`m loosing under the hood of this (48k & high)lights.I apreciate HELP with this "catalog question" or someone with expirience with this dac before. THANK YOU,KIKE