Can too many components on one outlet affect the sound of an amp?

I have a large house with the usual 15 amp circuit (actually two panels). I had two dedicated 10 gauge wire outlets put in and run to the main panel with one outlet behind each speaker to serve the monoblock amp there. Then along came ac filter boxes and regenerators.  Also sometimes I only had a stereo amp. To cut to the chase, I very seldom use the left side outlet.

Also, I have experimented with a great number of power filters, like probably twenty. I now use all HFCables pcs and their waveguide power center plugged into a 20 amp circuit. Since the surge on turn on for one big amp kept tripping my circuit breaker, I had to go to 20 amp breakers.

I have six components plugged into my power center with it wired to the wall outlet. Once I had seven components as I was using the BMC M2 monoblocks. I have never thought that I was adversely affected by having too much load on the circuit. I have, however, found the wall outlet to be critical. The house originally had Eagle outlets. Here again I have tried probably 15 different outlets. They too make a difference.

So electronics before the components can affect the sound, but I  doubt that you are near the limits on even a 15 amp circuit. If you were to trip a breaker, then I would be concerned, especially as you may have only 16 gauge house wiring. Most outlets now are configured to allow the use of 20 amp plugs, but I have yet to see anyone using such a plug to the wall.

You can break it down to the basics.  Current & voltage coming from any outlet will contain some form of noise, some more than others due to what is plugged into that same line circuit.  What and the only thing that could affect the sound quality from audio equipment is AC noise introduced on the line.  The rest is a current supply issue.  Eliminate the AC noise component and you have clean audio.  Most all floor / wall outlets are 20 amp circuits. Lighting is 15 amp circuit which it should be.  But I have seen where lighting circuits are tied into the wall outlets which is a big NO-NO.  Power conditioners/isolators like Monster Power etc. are a very good idea.  And a dedicated 20 AMP circuit as mention in another post for your power amplifier is also a very good idea.  Ground loops are death to audio systems, and are sometimes difficult to track down.  I have seen special duplexes for audio equipment sold for 500.00 plus.  What a joke!  save your money, a beefy 20 AMP duplex for 1.15 will convey the current and voltage to your piece of gear just as well as the touted special outlet, for ungodly amounts of money.  One other thing all homes have 14-2 gage wire for lighting circuits and 12-2 gage wire for all outlet circuits.  Or they better be to be in compliance with local code.

cleeds
"do you mean the safety ground------"
The ground is lifted only for the outlets in the audio, not from the main circuit board. You are absolutely right that it does not meet the code, when I sell the house, it will be set right. Therefore, I recommended caution. not for every one. It did make a significant difference though in sound. 

Try running your amp direct in the wall. Run your source gear and pre amp off the conditioner. Next separate digital from analog gear if possible.

To begin...an outlet is an outlet.  All are required to be 15 amp rated and all they do is pass power.  You can't hear any difference from one brand of outlet to another. Just make sure the integrity of the outlet is good and not old and fatigued.
Is it better to have multiple outlets on different circuits than just one?  Really depends on how many amps your main power amp will draw during critical demands or sustained demands.  If you are not listening at ridiculous spl's with inefficient speakers then I doubt that this is making any significant difference.  
One thing to keep in mind is the psychoacoustic difference between listening to music with a video source engaged and without.  Music is always more involving without any video content or visual distraction.
The power consumption of your other sources (video) will be negligible.
Other considerations are the quality of your AC coming into your home.  Power demands go up during evening hours.  Secondly, you can check your main service panel for power issues by using a multimeter.  Check both sides of your panel...they should be within 1-2 Volts of each other.  If not you could have an issue with your neutral wire or something else.