需求
“Draw a 9 V 2N5457 piezo preamp with gate bias, source resistor and bypass capacitor, drain resistor, input and output coupling capacitors, a 100 kΩ volume potentiometer, and a 10 kΩ tone potentiometer.”
接著試試Change the input capacitor to 22 nF.Change the volume potentiometer to 250 kΩ.
這張圖裡有什麼
看懂背後的決策。
01
JFET common source stage for high input impedance and gain
02
Passive volume control using a voltage divider
03
Passive tone control with RC low-pass filter
When building a preamp for piezo pickups that require high input impedance (1MΩ) and variable output level.