Try removing the A/D and D/A converter from your audio chain and check with your ears if it is the weakest link. I removed my Apogee Element (192kHz/24bit) and the sound becomes fluid and pure analog.
With good equipment like the SE Electronics Gemini II microphone, Blue Robbie preamp, a Violectric HPA V200 headphone amplifier and a Beyerdynamic DT770/DT880 headphone the difference is qualitatively perceptible. Of course 192kHz is better than 48kHz but the basic problem remains with Apogee Element AD/DA (Apogee sounds very good for the price but the analog sound sounds better).
“For years now people have been trying to figure out why their digital recordings don’t have the warmth and feel of analog tape recordings. We try using tube Mic Pres and great compressors, but there is still something missing. There is still that blurriness, that graininess and lack of depth that comes with digital recordings.”
Apogee Element does not support DSD but uses the same ADC conversion chip as RME ADI-2 PRO FS, Merging HORUS/Hapi and maybe Mytek Brooklyn ADC: AKM AK557x (PCM768/DSD256).
It is clear that the ADC chip is as important as the electronic circuit around it, PSU and clock jitter but in the end it is always the comparative listening that helps to better understand the specifications in real conditions (sound also has subjective aspects.). But even the digital coding system can be important if the purpose is archiving and not editing. In this case it seems that Merging like Mytek prefer DSD to be as close as possible to analog sound.
Why not create something like this to help potential buyers perceive sound differences? Here are comparisons of the same mix with various Lynx / Prysm / Forssel / Merging / Antelope / Lucid / … converters: http://www.shelterred.com/butterflies/