using cd unit for dac only

My cambridge 840C Azur cd player has an issue with the assembly housing the laser piece and thus the disc is skipping all over. To bypass this,I hooked up a Rega Apollo as a transport and using the 840C as a DAC only since it has a "digital in" feature--came in handy now---My question is--technically anyway-am I getting the same 840 C" sonic attribute using it just for it's dac----

Another route I took was Trying the Rega unit with a outboard Benchmark DAC1---but the dac 1 seems to creat a bit of a humming noise-audible only near the speaker-anyone else have noise issues with benchmark dac?