Bob,
It's very true for the jitter impacting a lot the sound of EQ plugins.
But that phenomen is added to a existing harsh top end due to the EQ itself.
I don't own the DAC-1 but I use the converters of my TC6000 wich are jitter immune too, and I still don't like the digital hi.
Concerning the range of settings, there is something else that I found strange too.
When EQ'ing with mid level digital EQ, I need to cut everything. And the more I cut (or boost), the more I need to cut (or boost) somewhere else : There is always "something" wrong.
No matter what the settings are.
So, if mixing tracks with plug ins, I often need to EQ a lot.
And 4 bands are sometime not enough (!), whereas with a good sounding EQ I can live with 2 self (+ maybe a parametric medium)... and be WAY happier with the results.
Now for me the smile is back
Best,
Salvator