El: an amp that derives its power source from the audio signal would be lower in linearity than a Class C amplifier. The end result would be that gobs of resolution would be lost. After all, rather than pass all of the signal onto the gain stage for further amplification, some of that signal would be absorbed and converted into drive for the power supply.
Other than that, your "concerns" are quite valid. If "audiophiles" would concentrate on the basic fundamentals of proper gear selection and installation, many of the "gadgets" being offered become inconsequential to achieving excellent results. I've seen WAY too many systems that were loaded down with expensive "tweaks" and achieving less than optimum performance simply because the basics of proper installation were being ignored or looked over. When one selects gear that is less than well designed and impliments it in poor fashion in their listening environment, subtle changes ( tweaks ) to the system help to band-aid all of the wounds that were previously wide open and exposed. When one adds up all the expenses of the "tweaks" that they spent taking this approach, they could probably have purchased better gear that was less susceptable to "tweaking" to begin with.
Given that most gear made today suffers from phenomenally under-designed power supplies though, and the AC signal that we are being provided with in most major metropolitan areas is so bad, i don't consider the PROPER filtering of AC to be a tweak. It is almost mandatory. That is, if one really wants to hear what their system is capable of, well set-up or not. Like anything else though, there are various products and designs available to attempt the proper filtration of a signal. Some are far more effective and / or deleterious to the results that one can achieve. Sean
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