Thats the reason for my purchase hopefully not add to the signal. I will not use the volume control at all. I will have it turned up all the way and it will be used as a pass through. I am using it pretty much as a switcher because my surround receiver does not have the functionality of a stereo bypass (a curcuit separate from the digital stage)and it takes away from the signal and sound. Having my CDP straight to the power amp achieves a better sound with greater dynamics and resolution than going CDP->sourround receiver->power amp. The CDP has a built in volume control so I can plug it straight to the power amp and control the volume.
Hopefully there won't be grain at all since I will have it full tilt on the volume and bypass the resistors that controls the volume. The grain you mentioned could be due to the use of resistors as volume control on the VDA-1. The Anthem Pre 2L SE has been a reference Pre for a lot of high end audiophiles.

http://www.quadloft.com/hometheater- new HT