Tweaking of power/inter/spk cables*,AC delivery-filtering-regeneration (very important),isolation products(dampers,cones,feet etc and CD treatments have yielded far more than a component switch in my experience. When the tweaks are done it makes it easier to hear the better piece shine or not if you will. As to a pre if you have sources/amp capable you need to try passive. Just try it. Sometimes less is more. A better power cord on my CDP took away silibance present in vocals. This was after trying several that did not take it away.
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