Amp preamp impedance matching...can anyone explain?

Reading this as well and I wanted to add my specs from my Marantz PM-KI-Pearl Integrated that I would like to entertain using as a preamp and then adding an amp...tube or ss still not determined.

The testing of this Pearl unit shows "The output impedance from the Preamp Out jacks was 217 ohms at high and middle frequencies, rising to 495 ohms at 20Hz."

Based on this information, does one still look for the above in the input impedance of 47k or higher?

Vineman, since the worst case (20 Hz) output impedance is known, just multiply that by 10 to calculate the minimum desirable amp input impedance.

495 ohms x 10 = 4.95K (minimum)

Nearly all power amps will meet that criterion.

Regards,
-- Al

Thanks for clearing this up here...

07-19-12: Dracule1
I have a tube DAC that uses a single 6SN7 tube with 1 microfarad coupling caps. I was told it has 8 kohm output impedance.

that is correct. impedance at 20Hz = 1/2*pi*20Hz*1e-6 = 7957.7Ohms, which could be rounded up to 8KOhms. The manuf wasn't lying! ;-)

I wanted to get this integrated SS amp but the input impedance is 10 kohm. So this is a horrible match, so I stayed away.

right again! a horrible match down the in bass region. Your system would have sounded tinny. So, good thing you stayed away.

But I really wanted that SS integrated.

better put a lid on that desire while you have this particular tube DAC! ;-)

Does the voltage gain play into this at all? The amplifier I am using is a McCormack DNA-125, which has 30db of gain. Its input impedance is 100 kOhms. I am using an Audio Research SP8 MkII preamplifier with it which has an output impedence of 1,000 ohms.

I had Audio Research lower the gain in my SP8 recently, but needless to say, the volume through my Vandersteen 3A Signatures still gets loud in a hurry.

I was wondering if someone could please recommend a low gain, solid state Audio Research amplifier that is rated between 100-200 watts per channel? I do not want a tube amplifier, and I do not want to get rid of the wonderful SP8 MkII.