CDP connected Directly to amp with variable ctrl

Hi, I have a Tube output CDP with variable volume control(Ah4000) and I'd like to connect it DIRECTLY to my Integrated amp which has a variable control in the back of the unit(NAD C370);just wonder if in this way would it sound equally good as using a conventional tube preamp ?
My other system: Analysis plus Oval 9 spkr cable;TruthLink IC;Quadral Ascent850 spkr.
Your opinion and suggestions is highly appreciated and thanks in advance
Simon