The lower the AC impedance feeding high-end audio equipment the better each piece sounds. And when the entire system is fed with low impedance power the results can often be breathtakingly better. But, how do engineers lower impedance?
That question’s not simple to answer but I am going to try. Basically, we need a few things: extra energy, a valve to mete it out, and a measurement system to decide how much and when. Definitely not something passive conditioners or simple wires and plugs are capable of.
The easiest way to think of a regenerator’s power amplifier is as a valve in the classic water example. It has a power supply with stored energy and a means of releasing however much of that energy is needed. For our analogy, we’ll imagine the wall AC plug as the main water source, the amplifier’s power supply as a reservoir, and the output of the AC regenerator as a valve. For powering equipment we need 120 volts (or double that outside this and a few other countries). Thus, we turn our imaginary spigot on just enough to attain a flow of 120 volts. Life’s good.
But then, something happens. A big and thirsty device begins sucking water out of our imaginary faucet at a rate greater than expected. The 120 volts of flow we once drops to 100. The system can sense the drop and turns the valve, releasing more of the stored energy and we’re back to 120 volts again. By carefully monitoring the flow, 120 volts can be maintained no matter of thirsty or satiated the connected amplifiers are.
I have just described the mechanisms at play in the power amplifier of an AC regenerator. If we use the term feedback in place of measuring device we exit the imaginary and move towards the real.
Feedback is the essential element in an amplifier that senses change in the output and relays that information back to the control valve for adjustment. The more feedback, coupled with greater energy storage and strength in the valve, is essentially the elements we focused on when we rebuilt the new amplifier for Ps 20, 15, and 12.