[Gumby]

How much does impedance matching matter between components ?  Example, a Bryston CD player will obviously match a Bryston integrated.  I notice that the input impedance specs vary from brand to brand of Integrateds, Preamps, etc.  One may be 11k ohms, another 30 k ohms.

When does it matter to pay attention to these details?,...or does it, ...or it’s all in the demo ?

[Speedskater]

With RCA or XLR analog interconnect systems, if the output impedance is well below 500 Ohms and the input impedance is 10 k Ohms or higher, there are zero differences.
Old vacuum tube circuits are a different ball game.