Control volume with DAC or Preamp?


My DAC (PS Audio Directstream) has a volume control and so does my preamp(Benchmark), of course.  What’s the best way to control the volume of my system to get optimum sound...turn the dac to maximum volume and use the preamp to make adjustments , turn the preamp to maximum and use the DAC for adjustments, turn each of them up part way? Or does it not make a difference?
wolverine1
Indeed, you, like me and many others, have found that quality preamps do indeed serve their designed purpose.

Of course George will tell you that your ears (or components) are wrong.

What's important is that future readers understand his bias, and that the only way to know for themselves is to try the alternative approaches in their system.

Clearly results differ in different systems and for different ears. 


@unsound DAC chips can control volume in the digital domain and many DACs use this feature of the chip to do so. In my own experience this leads to clearly inferior results compared to a pre. I would never consider using a DAC for volume control unless the DAC has a real analog pre stage of some kind, or at the very least an analog volume control chip. Not to say that it's any good, but adjusting volume in the analog domain is the first prerequisite.
@madavid0, So rather than for a reason, it’s for a preference? And I don’t post this to discount your preference.
Just for accuracy... The DS Dac is transformer coupled. You can see it here:
https://images.app.goo.gl/oDW85e3k2MKCXJP98

Same difference cap or trany coupled, they both will roll off the bass when used together by the input impedance of the next stage if not large enough as in this graph showing it’s bass roll off already starting at 100hz!!! and becomes more severe the lower the input impedance of the poweramp becomes, a 10k Class-D which many are would have zero bass output.
https://www.stereophile.com/images/914PSDSfig04.jpg

Cheers George