in the digital realm volume levels can be attenuated but there will be a loss of bit-detail resolution if the attenuation is significant from full volume -- whether you can hear this clearly as compromising sound quality is another matter entirely, but there can indeed be a loss of info in the last few bits of the datastream at low volume levels
this having been said, there are dacs that do the attenuation post d/a conversion (metrum jade, ayre codex, sonnet morpheus are three outstanding dacs that do this) ... i.e. at the analog output stage... this is hard and expensive to do (the same reason why good preamps are often expensive, there is real skill, technical savvy and often expensive parts involved in implementing analog domain volume attentuation without hurting the purity of sound)