I've been doing some experimenting with this very thing recently. Using dac's digital volume control least desirable, loss of bits means resolution losses. I also have three choices of passive volume attenuation available. Passive resistor volume control built into my Coincident Turbo 845SE, Schitt Saga (also resistor based volume control) on passive or tube buffer setting. I also have Coincident Statement MKII linestage for active pre with further upgraded Amtrans rotary selector (transformer volume control).
As I stated previously, dac direct to amp has always been least desirable going through many amp and dac combinations over the years. Passive with either the Schitt or Coincident Turbo third best. Schitt on tube buffer setting second best, adds some meat on the bone. Statement active best, none of the others can match the micro and macro dynamics provided by acitve. These added dynamics provide a much greater sense of real live performers in room. Other added sq improvements, just on a lesser scale.
Still, apples to oranges here, over 6k active vs. $400 plus nice 6sn7 tube in Schitt or questionable cost of passive built into Turbo. The marginal gains here make all the difference for me.