Amplifier Input Impedance


Why are so many high-power solid state amps designed with such low input impedances. Doesn't that really low input impedance limit the range of pre amps that can be used? Are there technical reasons why designers make these impedances so low? Why not design your muscle amp with a really high input impedance so it will potentially work well with all pre amps?
stickman451
help me out here, what is 1/10th of 100kohms?
Audiolabyrinth
that would be 100KOhms = 100,000 Ohms divided by 10 = 10,000 Ohms or 10KOhms.

The general principle here is that when the output impedance of the preceeding unit is 1/10th the input impedance of the proceeding unit, the output impedance of the preceeding unit has little effect on the (music) signal transfer - you get 90%+ of the (music voltage) signal to transfer & there is (very) little loss.
hope this helps.
I notice on my set up ,
Preamp : Reimyo output impedance is 560 ohm ,
Power amp: AES superamp AE 25 input impedance is 150,000 ohm .
This gives ratio of 267 times . Does it mean I have a total mismatch ? But I find my system sound very sweet , detailed and enjoyable .
I am no expert on such things , so will appreciate some explanation from FM s here .
I notice on my set up ,
Preamp : Reimyo output impedance is 560 ohm ,
Power amp: AES superamp AE 25 input impedance is 150,000 ohm .
This gives ratio of 267 times . Does it mean I have a total mismatch ? But I find my system sound very sweet , detailed and enjoyable .
I am no expert on such things , so will appreciate some explanation from FM s here .
02-23-14: Radni
I notice on my set up ,
Preamp : Reimyo output impedance is 560 ohm ,
Power amp: AES superamp AE 25 input impedance is 150,000 ohm .
This gives ratio of 267 times . Does it mean I have a total mismatch ?

Absolutely not! The 10X rule is a MINIMUM suggested requirement. Some manufacturers, like ARC, recommend a 25X to 30X MINIMUM impedance relationship. Obviously, the higher the ratio, the less likely there will be an impedance mismatch issue. Which should help explain your wonderful results.

But I find my system sound very sweet , detailed and enjoyable .