Amplifier Input Impedance

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 .

Suppose a system comprises a DAC with preamp and on-board analog volume control (generally I suspect analog volume has higher performance potential vs. digital volume control).

Let’s further suppose one has a separate high performance pure analog preamp w/high performance power cable and analog IC.

I suspect that the higher is a power amp’s input impedance, the more likely would listeners prefer overall performance with the above described DAC source direct to power amp, and the less likely would the above described preamp improve performance.

It may not be a coincidence that Bricasti’s M21 is a superior DAC with analog volume control (and separate DSD and multi-bit ladder type DACs), Bricasti does not make a separate preamp, and Bricasti’s power amps have very high input impedance: Bricasti specifies M15 input impedance of 200k ohm; Atkinson measured 170k ohm IIRC, which John called "usefully high."

There’s another potential fly in this ointment: subwoofer power amps, which always or often have very lower input impedance in the range of 10k-12k ohm. Systems with one or two sub amps are more likely to need an active high performance preamp.

If one wants a system with the flexibility to audition any power amp, again, a preamp would seem to be mandatory.

I have an analog FM tuner that's very sensitive to output loading, requiring an input impedance of 47Kohms (min.) on the connecting equipment. Unfortunately, it seems that newer preamps and integrated amps have input impedances much lower than that which really limits my choices.

Another problem area is for those with equipment that have output coupling capacitors connected to equipment with low input impedances. This could result in reduced bass performance.

Designers could easily achieve higher input impedances in their designs IF the requirement existed.