See that the gain of the circuit is equal to the Rb / Ra. Those who want to use the pre microphone, you can modify circuit to new as Figure 3 The feedback circuit for microphone.Check the operation of the circuit by adjusting the Knob.Connect the output of the circuit to the main amplifier and bring the good signal to the input of the circuit.To apply the power supply to this circuit connects correctly. How to help the solder is easy to clean pins all the time.
Because May cause equipment damage And copper may be peeling off. Be Careful of a beginner at every point soldering Requires heating the solder sufficiently to ensure that all solder points are very well equipped.If the number MPSA42 switches the position of the emitter and collector to the opposite direction.
The actual size of the single-sided copper PCB layout and the component layout.
