Greg wrote:
Pete KE9OA wrote:
As long as the source impedance of your microphone is lower than the load
impedance of your 897's mic input, you are fine. The impedance is close
enough anyway.

Its more about output level, relating to standard levels at various Z's.
A 100 ohm mic will have less output than a 1k. I really can't think of any
reason Z would matter, except a low Z mic would tend to have less RF
pickup,
but maybe not.


greg

Terminating a signal source in an impedance that is lower than for what the
source was designed, will reduce the low frequency response. The worse the
mismatch, the worse the LF rolloff. I learned that in my broadcast days...
a turntable preamp wanted to see = 10K ohms but the mixing console's input
Z was 600 ohms. The result was a very "tinny" sound that *nowhere near* met
our annual audio Proof of Performance test.

OTOH, loading a 100 ohm source w/ 1K ohm will result only in a
less-than-maximal signal level. That's ok as long as the preamp can make up
the signal level w/o adding undue noise.

73,
Bryan WA7PRC