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
Thankyou Ralph, You are the man in my book!, I do learn alot from you and Almarg, the both of you gentleman are a asset to us all!, I agree, my 100kohm amp does not lack in bass at all., help me out here, what is 1/10th of 100kohms?
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 .