Analyzing the power from the outlet

Proper voltage and current is easily measurable at an outlet as a start to make sure you are at least playing on a level field. What happens beyond that in regards to power and sound is not practically measurable it would seem. Trial and error is needed, but not blindly. Learn about solutions that solve particular problems, like reducing noise levels with line level gear and optimizing current delivery for power amps, and buy wisely. Lots of "noise" out there when it comes to high end power solutions that muddy the waters. Know the problem you are looking to solve and go from there to end up at a happy place soonest.

I like Pangea power cord products in this regard. They are not overly expensive and each product is clearly designed to solve specific problems as I related above. A very good place to start if one must. Noise levels are often significant with modern gear, especially computer/digital based gear and worth tackling at some point IMHO, but only after the main components in any system are working together well, as an improvement, not as a solution to change the sound in a major way.

I also recommend a decent power conditioner as a must for line level gear (not for current hungry power amps)in most any serious hifi system these days. Furman is a line I like, but even the common Monster strip/conditioner works well.

like Truman, I use a PS Audio regenerator (the P-3) and the results have been incredible. Getting clean, consistent power is now the basis from which I start any system I put together in the future. I want to add a dedicated line next with upgraded wiring, ground, etc.

You can do this rather easily using a modern Oscilloscope. You will need to play with the resolution, try several different Hz, from 100 Hz to several thousand per division. This is easy to see. I am an electrical engineer and this is a simple thing to do. Depending on your area, congestion and the type of loads, power can be very dirty. Your electric company generally is not too concerned about this. Simply Google "Measure noise on AC line."

Besides providing a stable voltage, a regenerator will also reduce or eliminate noise and distortion that is present on the incoming AC, since it is what generates the AC that is provided to the components it is powering. Essentially it consists of an oscillator generating a 60 Hz signal (or 50 Hz in some countries) driving a high powered amplifier which in turn supplies that amplified 60 or 50 Hz signal to the connected components, and a power supply which converts the AC from the wall outlet to the DC which powers its own oscillator and amplifier.

But I understood the amplifiers require internal oscillators to operate? Why do you need to add an external oscillator?

The bandwidth limitations of the power transformer will significantly reduce the frequency components of the noise that are above a certain frequency. Noise on the incoming AC will also be reduced by filter capacitors and decoupling capacitors that will be present at various circuit locations in the design. It will also be reduced by voltage regulator circuits that are generally used in audio components, other than in the high power stages of most power amplifiers and integrated amplifiers. Finally, it will be reduced by what is known as the power supply rejection ratio of the amplification and other circuit stages which process the audio signal.

If all this processing is in the amplifier, why would it matter what you do to the power before it arrives at the amplifier? Maybe I'm missing something. But it seems to me that this is the design challenge of building amps. In theory, amplifying a signal is straightforward -- you buy an opamp and insert it into the signal path. But, addressing the departure from theory is what adds the complexity and $1000s to the price an amplifier. The designer building circuits into the amp that mitigate the problems created by the power supply. How could you market an amp that only functioned with a pristine power supply?

But I understood the amplifiers require internal oscillators to operate? Why do you need to add an external oscillator?

An oscillator is something that generates a signal. An amplifier is something which boosts some combination of the voltage, current, and power of a signal. What I was describing was a power regenerator, which takes in AC power from the wall outlet, and sends out "regenerated" AC to the components that are plugged into it. Power is regenerated in the regenerator by amplifying a signal generated by a 60 Hz oscillator which it contains. As I indicated, the regenerator's amplifier and oscillator are powered by DC which its own power supply creates from the AC it receives from the wall outlet.

If all this processing is in the amplifier, why would it matter what you do to the power before it arrives at the amplifier?

No design can reject noise and distortion on the AC it receives to an infinite degree. A substantial body of empirical and anecdotal evidence exists suggesting that designs at pretty much all price points can benefit sonically if the AC they receive is relatively clean.

Regards,
-- Al