Power, what matters

We learned in yesterday's post that we can lower power line noise without too much difficulty. The challenge is selecting the appropriate technology, one that does the least sonic damage, while offering the greatest reduction in noise. Our rewards are blacker backgrounds. Valuable, yes, but not the biggest culprits when it comes to what can be done with power. The three areas of concern with power were also mentioned yesterday: noise, shape, and level. What comes out of our home's wall sockets should be a pure sine wave, nicely rounded on the top, symmetrical and without a lot of garbage on it. Unfortunately, that is rarely the case. What is actually coming out is distorted, usually flattened on the top. Here's an example of what I am writing of. Note how the tops of each sine wave are lopped off? Also note that in the middle of the sine wave there is a step, a little bit of discontinuity. This shape is no problem for most of what runs in your home: light bulbs, appliances, computers, radios. But when it comes to stereo systems of high quality, this can have a major sonic impact and needs to be fixed. The problem is most felt on the flat topped waveform. The small area that is missing is where the energy your stereo system needs is trying to be delivered - and it's missing! This missing energy manifests itself as higher ripple levels in the attached power supply - a significant problem in a power amplifier, less so in a regulated supply, like a preamp or DAC. Sonically, the increased ripple is like a smaller power supply with fewer capacitors for energy storage. Wimpier, with less impact and fullness to the sound. Filling in those gaps makes sure whatever size power supply your unit was designed with, gives you full benefit of all you paid for. Power filters, and power conditioners cannot help restore what's not there. Filters can only remove, they cannot add. To add the missing power, you need a regenerator, an active device that can add back missing energy. But shape is only half of the serious issue. An even bigger one looms on the horizon.