Impedance matching is nothing new
It is the attempt to make the output impedance of a source equal to the input impedance of the amplifier to which it is ultimately connected. This is pro-audio engineering 101 and to studio engineers, finding and fixing impedance mismatch between studio equipment is as essential as asking a plumber to find and repair a leak.
Does this problem exist in audiophile systems?
Absolutely! Audiophile components come in much greater varieties when compared to those in pro-audio. Battery vs linear vs switching power supply designs, tube vs solid-state designs, discrete vs IC designs. Each has very different output impedance. This variety results in widespread impedance mismatch and it often exists between the source component and the preamp or integrated amplifier.
Many audiophiles are not aware that the performance gap between what they hear in the dealership demo and what they hear at home after the purchase is a direct result of impedance mismatching between the new machine and the rest of their system.
So why is it hardly ever mentioned?
Because no one in the HiFi industry, from manufacturers to dealers to established magazines want to talk about this problem. Imagine how many people (consumers) will be discouraged from this hobby if they knew how difficult it is to find two pieces of perfectly matched equipment? Furthermore, no manufacturer wants to publish a list of what matches and what doesn’t with each of their products. This industry, like any other, must simplify its message to keep its valued customers.