This is Pre Amp purpose of Circuit, a circuit that is easy to use and can be used to input various types of up to 4 inputs such as where a microphone that is sensitive signal about 50 mV. Position 2 for the tape. sensitive signal about 100 mV. position 3 for the tuner. Sensitive signal of about 300 mV. Position 4 for a CD with sensitive signal about 500 mV. The circuit will expand the signal output from a 1 Vrms. Signs that this is a signal strong enough to drive. to the power amp.
This circuit uses IC Op Amp NE5532, which number in the dual (Dual Opamp) is to use a stereo. You can use the legs to rest the image structure IC NE5532.
Principle of the circuit, it is when the input signal to the R1 and C1 are coupling and filter the signal to the pin 3 input of IC1. This will expand the signal a horizontal inverse Ding or extend the signal did not return. phase out to the output pin 1. by R3, R4, R5, R6 and R2 is the rate of growth and the switch S1 (Selector) to select the channel position Each box location to receive the signal strength of different inputs. For example, if selected to a position to receive the signal strength of 50 mV. And can calculate the growth rate of output from the AV = (R3/R2) 1 = 21 times.
Then be multiplied by the strength of the input signal entered into, it will be a strength. The output signal out. Each position of the input to the audio output from strength to 1 Vrms.