Power everything

Very simply put, a pwr conditioner lowers AC line noise and EMF interference. Now that the noise level in your system is lower, you can hear more detail in the music. A conditioner will usually have a surge protector that will trip the circuit in case of a line spike in the way a circuit breaker works.

In areas where the power grid is especially dirty and unstable, a power regenerator is called for. Many of these units are still called Power conditioners depending on the manufacturer. This is an "active" unit where the AC line voltage is converted into a DC signal and processed into a clean sine wave equal to the correct voltage to run your system.
The first type of pwr conditioner I noted is a "passive" device; it is really acting more like a filter.

Downside of an Active Conditioner is the expense. So, you need to determine the conditions of where you live; dirty, noisy power line, power outages, lightning strikes.

Mucho info in the archives, here's one...

http://forum.audiogon.com/cgi-bin/fr.pl?hbest&1034192322&read&keyw&zzbest+power+conditioner

If you are looking into upgrading your power source, start with a dedicated AC line. It will greatly reduce noise and no more sharing the line with any appliances in the home.

most passive power conditioners in the market substantially constrict the flow of current into amplifiers thereby sucking the life out of the music.

1. Agree. Amps will sound better when plugged into the wall. Some conditioners will lower the noise floor of an amp, but at the expense of imaging and dynamics for starters.

2. I started the Op off with the very basics in the concept of Power. Now we've moved on to the advanced class. That's OK.