OK, but most external DACS can also can control the volume and provide a proper load. What would be the point of this product if you only have digital sources?
This preamp could be a suitable solution also for those who have only one digital source (CD player or DAC), which either does not have volume control or has a volume control, but for some reason it is not preferred by the user. Some people still consider digital volume control in the DAC to be inferior and prefer a traditional separate analog preamp.