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Acoustic pickups

9/5/1997 5:20 PM
Acoustic pickups
I can see that Electric guitar-talk runs rampant in this discussion. I've got a question about acoustic pickups, but I think that it's electronic enough in nature... :)  
I'm considering purchasing a Sunrise magnetic soundhole pickup and utilizing it with an on-board, active preamp designed to blend 2 signals (piezo and mic). The sunrise is actually not made to go with this preamp, but from what I hear, it will work; the only question is gonna be the sound quality.  
The Sunrise is a high-impedance pickup; they recommend a preamp with around a 1 Megohm input impedance and around 12-20 db of gain. The preamp is rated at 10 megohm and about 10 db of gain. Now, the question...  
How much sound quality will I lose because of the mismatched input impedances?  
I hope this is not over anyone's head...  
9/5/1997 8:24 PM
Steve Morrison

The answer... None!  
It's not neccessary or even desirable to match impedances where only voltage amplification is involved. A good rule of thumb is to have an input impedance at least ten times greater than the output impedance you intend to drive it with, and that would seem to be exactly what you have.
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