This circuit is indicated to operation with piezoeletric transdicers or other with high impedance caracteristic. The circuit has a low voltage gain (less than 1) but the output impedance is low, resulting in a high power gain. The circuit can be powered from sources in the range between 9 and 15 V and the current drained is very low. Any general purpose JFET as the BF245 or MPF102 can be used. Figure bellow shows the circuito simulated in the Multisim Blue. The signal gerenator applies a 1 kHz sine wave signal with 500 mVpp. Observe the adjustments for the oscilloscope.