In respect to the OP, my experience parallels Larrybou's, but I find that critical listening for differences in gear (or whole system evaluation) requires at least two efforts on the part of the listener that tend to oppose to each other. On an ongoing, momentary basis, you must be ready and able to take inventory of a rather exhaustive length and breadth of various sonic categories and traits in the attempt to track and analyze them - to remain vigilant and on point enough to follow the sonic aspects you're concerned with. That is to say we must concentrate. And yet not lose sight of the role of those aspects in the overall picture, or the Gestalt. That is to say we must also be relaxed. This is not only a hard state, I feel, to both attain and to maintain, for whatever we might want to consider a useful purpose, but I find it's sometimes further complicated by an additional circumstance.
When I first heard the 25th anniv. edition of McCartney's Band On The Run CD, on it Paul spoke of an instance in which he recalled he had spent so much time and studio effort in an attempt to narrow down his choice between 2 different versions of one song (the title escapes me) to be chosen for the initial single release ahead of the album, that he found he no longer could rely on his own instincts for knowing which version he should choose for that single's release...IOW, he had lost his perspective on how to gauge the public's reaction on hearing it for the first time. After his producer learned of the choice between the two Paul had made, he called him up and told him that he thought Paul had made the wrong one. Not long after, it began to click for Paul that his producer had been right.
That actually happens often with artists and it's referred to simply as "getting too close to your work". It happens to audiophiles, too, I believe. And we're not known as audio"philes" for nothing. Listening for evaluation's sake is likewise a creative process that also requires a certain amount of passion, aesthetically, to see through to completion (however you may objectively define that completion). We must be sufficiently on point and yet also remain relaxed as possible, but there may come a point in it where you can simply get too close to the work and you are forced to back off for a while to keep from just spinning your wheels. Sometimes the best cure for it is a self-imposed absence...whether that's days, weeks, or whatever is always up to the individual. But, over the years I've found that when I've returned from such a prolonged absence as that, it is Far easier for me to get a handle on things than when I last left it - a very good 'reset button'. But, the give and take between concentration and being in a relaxed state does seem to force evaluation to be more of a long-term thing, to me. In all this, the truly relaxed state for us may end up being the most elusive.
