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Low noise tape head preamplifier

This is a low noise tape head preamplifier that good sound quality. Because use LM387N that is the low noise ICs and is designed for the specific preamplifier.

Low noise tape head preamplifier


Figure 1 is Circuit diagram of this project.

Maximum the output at 1 volts which is is high enough to drive easily the high power amplifier. The input can be connected with the tape head that have the resistance between 100-600 ohms.

The circuit has a very high growth rate, when apply the power supply to the circuit in first. The circuit not works immediately, have to briefly wait so can listen to sound at the output.

How to builds and uses
In Figure 2 is actual-size of Single-sided Copper PCB layout and Component layout.

actual-size of Single-sided Copper PCB layout and Component layout
Figure 2

The applications for this circuit. We must connect the negative of tape head to the main ground, to prevent the noise signal, especially from radio signals.

The parts you need
IC1_____________LM387___Low Noise Dual Pre-Amplifier
C1, C5__________1uF 50V___Electrolytic capacitors
C2, C3__________100uF 16V___Electrolytic capacitors
C4, C6__________10uF 16V___Electrolytic capacitors
C7, C8__________0.0033uF 50V__Ceramic capacitors
C9_____________0.1uF 50V_____Ceramic capacitors
R1, R6__________240K____ 1/4W Resistors tolerance: 5%
R2, R5__________27 ohms_________”________”_______
R3, R4__________1M_____________”________”_______
R7, R8__________30K____________”________”_______

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