Is the DAC the digital equivalent of a cartridge.

mahgister, That's an interesting thought if the question was not what the question is.  For the question that is, the thought is irrelevant.

I am snooping alll the time. What the cartridge does with a record is similar to what the DAC does with the digital signal it recieves. What has schocked me is how important  the USB cable is. I have 5 DACs near my writing position. With a particular cable, one of them sounds nearly identical to another one using a different cable, If I switch the cables they are very different. The match between a cable and a DAC is more like romance than science!  You don't have to spend a fortune on a cable. My best cable (on my two best DACs, not all of them) cost only $149 from Zavfino in Canada. The improvement in "Transparency" and "depth" is immediately obvious. If you buy a used cable you save $$ and don't have to break it in.

@mikelavigne I'm not an engineer, but an RiAA curve is nothing like converting digital info into analog signal.  From my understanding an RIAA curve adjusts the high and low frequencies of the signal boosted by the phono stage.  Phonostages are super important, but they are nowhere near what DACs do.  

Nobody said RIAA EQ was anything like the number crunching, filtering, and shaping of DACs. This is a weak analogy to begin with - and the idea was that both phono stages and DACs do "signal processing", in a VERY broadly general sense. Which is true, if not very useful.

And personally I feel that the SONIC impact of phono stages in a high-end rig is extremely large - typically much more than the differences I’ve experienced between DACs. We're talking about voltage amplification factors beyond 1,000x (60dB), so there's that. But again, I’ve gone way further into analog playback than I ever did with digital.