Piezo's require high impedance to produce full frequency response, especially in the lows. I put Shadow saddles on my P bass back in 1983, and I ended up having to add a capacitor in series to lower the low end as it was so much greater than the magnetic pickup that it made the P pickup sound thin by comparison.
Most piezos need 5-10meg ohm inputs. The more mass to the piezo, the more low end. Some pickups put out too much low end into 10megs, that the impedance of companion preamps (like K&K) is only 1meg to purposely limit the low end.
I put a decent active preamp in my Dean 5 string acoustic (the original controls were passive) and I will have to lower the input impedance as the low end is excessive and causing feedback problems.
Most piezos need 5-10meg ohm inputs. The more mass to the piezo, the more low end. Some pickups put out too much low end into 10megs, that the impedance of companion preamps (like K&K) is only 1meg to purposely limit the low end.
I put a decent active preamp in my Dean 5 string acoustic (the original controls were passive) and I will have to lower the input impedance as the low end is excessive and causing feedback problems.
