For the technically-minded among you…
It’s not foo but the marketing is trying to lead you to believe there is a problem where there almost certainly is not. And then providing an overly expensive solution!
Impedance mismatch between recording equipment, microphones, electric guitars, mixing desks etc can be a problem and there are low cost solutions for this.
Most HiFi is designed so that the input/output impedance is appropriate, so this problem doesn’t really occur. It could be a problem if you do stuff like CD to power amp via passive pre, say, depending on the exact equipment.
Whether this $200 device is the best buffer is another question!
Even with passive pre-amplifiers I’d expect the output impedance to be low enough not to cause problems. Depending on design, as you say.
There may be a few valve oddities with high output impedance. Otherwise low impedance source to high impedance load is almost always the case with hifi. No buffers, DI boxes, or matching transformers needed.
This is simply borrowing a problem that exists with studio and live equipment and trying to apply it to home audio. Poop.
Impedance matching does two things - it maximises power transfer and it reduces signal reflections which occur at changes of impedance. The only place in a domestic audio system where power transfer matters is at the end, after the power amplifier (the clue is in the name) which should be matched to the speakers. The rest of the system needs voltage, not power. Impedance matching can throw voltage away, meaning that more amplifier gain is needed and signal-to-noise gets worse. If you really need a signal buffer then get a proper buffer (better still improve the system to avoid the problem). If you don’t need it then don’t bother.
But it has a wonderfully scientific graph?
It’s Red! Does it come in any other colours.
Thanks for enlightening me everyone.