This circuit is a pre tone control using NE5532. In a three circuits of preamp tone controls by NE5532 is a very popular. But it has details are not clear. We recommend the low noise pre tone control circuit 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.
Figure 1 The circuit diagram of Low noise pre tone control circuit using NE55532
In Figure 2 The actual-size of single sided copper PCB layout and the component layout.
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
Q1,Q2____________ BC557 or MPSA42
R1_______________ 47K Resistors 0.25W x2
R2_______________ 1.2K Resistors 0.25W x2
R3_______________ 1M Resistors 0.25W x2
R4_______________ 100K Resistors 0.25W x2
R5,R6,R8,R14______ 2.2K Resistors 0.25W x8
R7_______________ 270K Resistors 0.25W x2
R9_______________ 1.2K Resistors 0.25W x2
R11,R12,R13,R17___ 10K Resistors 0.25W x8
R14_______________ 3.3K Resistors 0.25W x2
R15_______________ 4.7K Resistors 0.25W x2
R16_______________ 470 ohms Resistors 0.25W x2
R18,R19,R20,R21____ 100 ohms Resistors 0.25W x4