Phomchick, you are under a couple of false assumptions.
1: A straight line with gain is desirable
Answer: Sometimes no it isn't.
If the dac with volume control makes the system sound sterile and going through a good tube preamp adds some warmth that makes the sound much more enjoyable how is the straight wire with gain that makes you not want to listen to the system a bad thing? Sometimes adding the right colorations are a good thing.
2: The dac may not have a real preamp stage, sometimes you get a decent digial attenuator that does bit restriction to change volume, others use a digital volume control which is discrete resitors on a chip, while others use a potentiometer, while others could use switched resistors with realys to open and close the resistors.
So unless the "volume" control is really good that dac/preamp may actually alter the sound going through it via the volume control.
3: Many dac/preamp aren't real preamplifiers but are just the output stage of the dac with a volume control and therefore may have difficulties driving an amplfier or longer cable runs optimally.
Dave and Troy
Audio Doctor NJ
1: A straight line with gain is desirable
Answer: Sometimes no it isn't.
If the dac with volume control makes the system sound sterile and going through a good tube preamp adds some warmth that makes the sound much more enjoyable how is the straight wire with gain that makes you not want to listen to the system a bad thing? Sometimes adding the right colorations are a good thing.
2: The dac may not have a real preamp stage, sometimes you get a decent digial attenuator that does bit restriction to change volume, others use a digital volume control which is discrete resitors on a chip, while others use a potentiometer, while others could use switched resistors with realys to open and close the resistors.
So unless the "volume" control is really good that dac/preamp may actually alter the sound going through it via the volume control.
3: Many dac/preamp aren't real preamplifiers but are just the output stage of the dac with a volume control and therefore may have difficulties driving an amplfier or longer cable runs optimally.
Dave and Troy
Audio Doctor NJ