Priz, except of course for amplifying the sound, a well-designed receiver/amplifier is supposed to pass it through without adding any sonic characteristic of its own. Flat 20-20KHz response and inaudibly low noise and distortion are the requirements, and many moderate-cost units, possibly including your Sony, can meet those requirements. If so, it's already amplifying transparently and there won't be any sound difference when you don't apply tone controls or other sound processing features.

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Enjoy the music, not the equipment.