A pre tone control using NE5532. In a three circuits of preamp tone controls by NE5532 is a very popular.
Figure 1 The circuit diagram of Low noise pre tone control circuit using NE55532
But it has details are not clear. We recommend the Low noise pre tone control circuit using 4558 instead. We use the a NE5532 is heart of circuit. It was a very interesting Ics because have special features of the low signal noise, so commonly used in high class amplifier.
Use: 15V Dual power supply
How to builds.
We assemble all parts on the PCB as Figure 2 the polarity of electrolyte capacitors must be correctly put on PCB.
On PCB layout is used for transistors – BC557 or BC560C noise transistors types. If the number MPSA42 to switch the position of the emitter and collector to the opposite direction.
Things To Be Careful for beginner at every point soldering Requires heating the solder sufficiently to ensure that all solder points are very well equipped.
And be careful not to heat the solder too hot, because May cause equipment damage And copper may be peeling off.
How to help the solder is easy to clean pins all the time.
When assembled and checked well.
To apply the power supply to this circuit, connects correctly output of circuit to the main amplifier and bring the good signal to input of the circuit. Check the operation of the circuit by adjusting the Knob. Obtain the desired result.
Modify the pre mic circuit.
Those who want to use the pre microphone, you can modify circuit to new as Figure 3 The feedback circuit for microphone
The Parts you need.
IC1: NE5532 low noise OP-AMP or LM1458 or LM4558
Q1, Q2: BC557 or MPSA42, PNP 0.1A 40V Transistors
0.25W 1% Resistors
R5, R6, R8, R14: 2.2K
R16: 470 ohms
R18, R19, R20, R21: 100 ohms 0.5W 1% Resistors