I have bought pioneer's vsx-53tx av receiver and, since in stereo it' not at my taste, I am considering buying amplifier Nad C270.Does anyone knows how much av receiver as preamplifier degrade sound comparing to combination of real preamplifier(for instance Nad's C160),and should I go for integrated amplifier like Nad's C370 instead of combination VSX-53tx+C270. Thanx : )