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previous: Gustav 10 meg will let the piezo sound goo... -- 4/19/2000 3:50 PM

Re: building onboard active preamps

4/21/2000 9:44 AM
AMZ	Re: building onboard active preamps You don't need the diode clamps. A jfet is not susceptible to static damage like a mosfet. If you forward bias the gate of a jfet it just acts like a silicon diode. (My Fat Gnat design uses jfets as diode clippers) If you want to protect the jfet from over-current conditions, you could put a small series resistor before the gate of the jfet but I do not think it is necessary. 10M input Z is the very minimum that I would recommend for piezos. -Jack

4/21/2000 9:44 AM

AMZ

Re: building onboard active preamps

You don't need the diode clamps. A jfet is not susceptible to static damage like a mosfet. If you forward bias the gate of a jfet it just acts like a silicon diode. (My Fat Gnat design uses jfets as diode clippers) If you want to protect the jfet from over-current conditions, you could put a small series resistor before the gate of the jfet but I do not think it is necessary.

10M input Z is the very minimum that I would recommend for piezos.

-Jack

Replies:

Gustav Jack I was thinking of the voltage ... -- 4/21/2000 3:51 PM