One 20A line is not overkill, and may help. The reason I say "may" is its hard to know how the house and panel is wired. Often times systems are plugged into ordinary wall outlets, which because houses are wired for average use and to save money this could mean the AC goes from one outlet to another with maybe a half a dozen outlets on the same circuit. Worst case the system is the last one. In this case the line will probably be a big improvement. If you DIY. The minute you have to pay an electrician then there's usually half a dozen things you could do for less and hear a lot more improvement.
The reason I know, I've actually done this stuff, run the lines- and more than once- myself.
You have good reasons for keeping what you have, so what I would do is avoid anything similar to the analytical sound you have in favor of more neutral (in the true sense of the word) wire like Synergistic. This will feel warm relative to the sterile gear you have now but since you do listen to actual music then I think that in time you will come to realize what you now think of as color and rolloff is actually a more natural sound and what you are hearing is not less detail but less etch and glare.
Take your time, try and listen and when reading pay attention to how things sound not how things measure. Here are the specs that matter: speaker sensitivity, you want 90dB or more. Amp power is almost irrelevant, since if you got at least 90dB speakers then anything over 20 or so watts is good. Cartridge output, a little more complicated but similar to speakers a medium output greatly simplifies amp selection. That's about it for specs! And yes my system really does reflect that philosophy.
The reason I know, I've actually done this stuff, run the lines- and more than once- myself.
You have good reasons for keeping what you have, so what I would do is avoid anything similar to the analytical sound you have in favor of more neutral (in the true sense of the word) wire like Synergistic. This will feel warm relative to the sterile gear you have now but since you do listen to actual music then I think that in time you will come to realize what you now think of as color and rolloff is actually a more natural sound and what you are hearing is not less detail but less etch and glare.
Take your time, try and listen and when reading pay attention to how things sound not how things measure. Here are the specs that matter: speaker sensitivity, you want 90dB or more. Amp power is almost irrelevant, since if you got at least 90dB speakers then anything over 20 or so watts is good. Cartridge output, a little more complicated but similar to speakers a medium output greatly simplifies amp selection. That's about it for specs! And yes my system really does reflect that philosophy.