I don't doubt my ears when differences in the sound of components are to a very substantial degree. If I do catch the upgrade bug, it would be after several years of listening to my current system and then upgrading each component at a time, preferably at least a year apart. Before this, I read as many reviews as I can and then make a final decision based on my ears alone and how the new component synergises with the rest of the system.
To quote a character in the movie Ronin, "If there is any doubt, there is no doubt". So, don't make that upgrade if there is any doubt at all in your ears and in your mind about the "improvement" in sound. I find differences in digital components and speakers are more easy to detect by ear, probably because the technology would have improved by leaps and bounds after about 3 years with your old ones. Power amp differences are not so easy to hear.
But if there is an itch to upgrade, go for something that is several times the quality of the old one to remove any doubt(here is where all the reviews, especially the comparative ones, have helped me). If I can't afford the upgrade, I leave my current system alone for economic reasons.
To quote a character in the movie Ronin, "If there is any doubt, there is no doubt". So, don't make that upgrade if there is any doubt at all in your ears and in your mind about the "improvement" in sound. I find differences in digital components and speakers are more easy to detect by ear, probably because the technology would have improved by leaps and bounds after about 3 years with your old ones. Power amp differences are not so easy to hear.
But if there is an itch to upgrade, go for something that is several times the quality of the old one to remove any doubt(here is where all the reviews, especially the comparative ones, have helped me). If I can't afford the upgrade, I leave my current system alone for economic reasons.