How does the input impedance of an amplifier effect it sonically?


I understand the effects of an output to input impedance miss-match, but what I don’t understand is
why there’s such wide range in (especially input) impedances. Most tube amplifiers have a very input impedance. Solid state on the other hand has impedances that range from 5-250k. Why so much variance and how does it effect the sound of an amplifier, if it does at all?
hiendmmoe

Showing 2 responses by hiendmmoe

So I assume 1/10 isn’t going to enough of a safety net when matching preamp to amplifier input impedance. Since impedance can vary with frequency and most manufacturers don’t provide accurate numbers 1/20 sounds like a safer bet when matching pre to amp.
Is it then more important to know the correct value of the output impedance of the pre-amp at 20HZ than to know how accurate the input impedance of the amp is.
As for the amplifier input impedance is 20HZ also the number I should look for when a specific input impedance is given. If I understand correctly, 20hz is where the amplifier will show its  minimum value and any higher specification (frequency) given for impedance  is not its true value.