Peak demand

In yesterday's post, I said that today we'd discuss how to increase the size of the power supply capacitors inside connected equipment. A tall order, indeed, but I got sidetracked. So many of you have written me asking about a certain statement made by my friend, Garth Powell at Audioquest. When asked about regeneration, Garth had correctly said that it's great for some things but if not properly implemented, not for others. The only mistake Garth made was including Power Plants in his list of regenerators. The issue has to do with peak current. To lower impedance and produce regulated, perfect sine waves into a hungry power amplifier you need energy. A LOT of energy in the form of peak current. If we remember, sine waves are formed by voltage and supported by current. And it is the combination of voltage and current that makes all this work. I like to use an automotive analogy to help explain voltage and current. Think of voltage as the spinning motor and current as the horsepower need to keep it spinning under load. As you're driving along a flat highway at 60 mph your foot is steady on the gas. As you climb a hill the engine's RPMs begin to fall and you slow down. You need to step harder on the gas pedal to raise back up those RPMs. You are adding energy. The combination of the spinning motor and the energy available to keep it spinning are expressed in terms of horsepower. In an amplifier, the voltage is the spinning and the current is the motive force. We express this in terms of wattage. In a regenerator the output AC sinewave feeding your equipment is perfect. As it rises in voltage (faster spinning in our auto analogy) we need more current to keep it going. But what happens when the equipment we are attempting to power's capacitors are empty and need refilling? (it's as if suddenly there was a massive hill to climb). We need gobs more energy (current) applied and quickly! This is called peak demand because it happens at the peak (or the tip) of the AC regenerator's sinewave. And here is where Garth is correct. With few exceptions, AC regenerators fall short of having enough peak current available. When this happens we get increased distortion as the sinewave collapses. For most regenerators, we'd be better off going straight into the wall socket. But, not a Power Plant. Power Plants deliver significantly more peak current than what is available from the wall. We routinely deliver peaks of 70, 80, even 90 amps to the load. The wall socket's lucky to deliver 15 to 20 (on a good day). Where does all this extra current come from? It is stored in the many capacitors inside a Power Plant. Lastly, this might also answer why manufacturers don't typically build proper regeneration into their products. The number of caps, transistors and pounds of copper and iron necessary are not for the faint of heart.