There are four functions that any line stage of a preamp has to be able to do:
1) provide volume control
2) add any needed gain
3) select inputs
4) control the interconnect cable to the amp/prevent it from having a sonic artifact
Its the last function that is the least understood, and thus not realized by many preamps and DACs. A passive control could otherwise do the job if the DAC had enough output (which it should; Redbook standard sets it higher than the overload voltage of most amplifiers).
The problem is coloration from the cable and proper volume control in most cases. Individual results can vary quite a lot due to installation so really the only way to deal with this is audition.
I myself prefer to use a preamp as I have yet to find a DAC that really controls cables and I still have other sources (I still listen to the FM radio, tape and LP). Many DACs are great but have poor volume control systems (IOW, cause a loss of resolution as the volume is reduced). So I generally run them at full volume and control the volume from the preamp.
1) provide volume control
2) add any needed gain
3) select inputs
4) control the interconnect cable to the amp/prevent it from having a sonic artifact
Its the last function that is the least understood, and thus not realized by many preamps and DACs. A passive control could otherwise do the job if the DAC had enough output (which it should; Redbook standard sets it higher than the overload voltage of most amplifiers).
The problem is coloration from the cable and proper volume control in most cases. Individual results can vary quite a lot due to installation so really the only way to deal with this is audition.
I myself prefer to use a preamp as I have yet to find a DAC that really controls cables and I still have other sources (I still listen to the FM radio, tape and LP). Many DACs are great but have poor volume control systems (IOW, cause a loss of resolution as the volume is reduced). So I generally run them at full volume and control the volume from the preamp.