I've got a classic integrated amp (Denon PMA 1600) into which I feed the signal of an external DAC (Cambridge Audio DAC Magic 200+). Now both the amp and the DAC have individual volume knobs - the amp an analogue one, the DAC a digital one. I've gotten used to using both simultaneously, as the amps volume progression is a bit too steep - it gets too loud too fast, especially late at night - and the DAC steps in with more intricate adjustments. Now I've been wondering whether this setup may have any drawbacks, sonically or technically? After all, the DAC does have the option to disable volume control altogether and go into fixed-level output - why would they bother implementing such a feature?