This circuit is a complete application is 2.1 amp, two satellite speakers for TDA and one for the subwoofer, making the 2.1 system, widely used in commercial applications as an amplifier for computers, which may give an increased in its audio system with a stereo amplifier + bass amplifier (subwoofer).
Description of the amplifier circuit with TDA 2030
The circuit is divided into 3 parts: power supply, amplifier, stereo amplifier and bass amplifier (subwoofer).
Power supply circuit and pre + low pass filter for the sub power supply
The power supply is of symmetric type, using a transformer, 110 or 220 with dual secondary 12 volts and 3A current. I recommend using a fuse and a switch before the transformer. B1 is a bridge rectifier least 100 volts / 4 A, an example that can be used is GBU606, the filtering circuit is formed of the capacitors C1, C2, C3 and C4, the electrolytes can have values from 4700μF . The power supply for the op amp Highpass filter, is used three terminal integrated circuits 7812 and 7912.
Circuit of the amplifiers of satellite speakers
The left and right channels give exactly the same, let’s see how the left channel: LIN is the audio input jack, which is coupled by C20 to the pot volume adjustment, it is a double pot, and set the two channels simultaneously. R19/C22, helps to improve the signal of the treble. The capacitor C21 couples the signal to CI6 TDA2030, after amplified audio output is pin 4 of integrated. The resistor R7 and R9 are responsible for feedback, so by changing the value of R7 can increase or decrease the gain of the amplifier. R20 and C23 form the compensation network for the speakers.
Circuit pre and Amplifier Subwoofer
The signal comes from the subwoofer to the left and right channels by resistors R15 and R10 being decoupled by capacitor C12, is applied in the operational amplifier 1 IC4A NE5532, which forms a pre-amplifier to boost the signal by 6 times. Determined by R6/R8 resistor.
The components C9, C10 and R10 form a low pass filter in this case is calculated to 200Hz. After leaving IC4B the low frequency audio through the potentiometer P1 that makes the volume level, then forwarded to IC3 is what makes the subwoofer amplifier, the operating principle is the same as satellite amplifiers.
TDA2030 2.1 – Schematic of the power amplifier – Click to enlarge the diagram
Part List for assembly of power audio amplifier for 2.1 – TDA 2030
|Part||Value / Description|
|Resistors 1/4 W 5%|
|R1, R14, R20||10 – Brown, Black, Brown, Gold|
|R2||22k – Red, Red, Orange, Gold|
|R3, R5, R10, R11, R15, R19||10k – Brown, black, Orange, Gold|
|R4, R8, R9, R16||470 – Yellow, Violet, Brown, Gold|
|R6, R12, R17||33k – Orange, Orange, Orange, Gold|
|R7, R13, R18||4.7k – Yellow, Violet, Red, Gold|
|P1||10k – Potentiometer – Volume Adjust Bass amplifier*|
|P2||10k – Double Potentiometer General volume*|
|C1,C2, C7, C10, C14, C15, C17, C21, C23||100nF – 100n, 104, 0.1 – Polyester Capacitor|
|C3, C4||4700µF/35v – Electrolytic Capacitor|
|C5, C6, C8, C12, C13, C18, C19, C20||10µF/25v –Electrolytic Capacitor|
|C9||220n – 220n, 0.22, 224 – Polyester Capacitor|
|C11||47µF/25v – Electrolytic Capacitor|
|C16, C22||2n2 – 222, 2n2, 2200 – Electrolytic Capacitor or Ceramic|
|IC3, IC5, IC6||TDA2030A – IC power audio amplifier|
|IC4||NE5532N – Double Op Amp|
|IC1||7912 -Integrated Circuit Negative Voltage Regulator – 12V|
|IC2||7812 –Integrated Circuit Positive Voltage Regulator +12 v|
|B1||Bridge rectifier100V 4 A Ex:GBU606|
|Connectors and functions
|L-IN||Connector 2 terminals audio input left channel|
|L-OUT||Connector 2 terminal audio output left channel|
|R-IN||Connector 2 terminal audio input left channel|
|R-OUT||Connector 2 terminal audio output right channel|
|SUB||Connector 2 terminal audio output Subwoofer|
|AC||Three-pin connector for the transformer|
|J1, J4, J5, J6, J7||J12MM – Bit of wire|
|J2||J5MM – Bit of wire|
|J3||J7MM – Bit of wire|
|Transformer 12 +12 / 3 amps, wires, box for the amplifier PCB, heat sink for the IC TDA, etc..|
Appearance of some components used in this assembly TDA2030, NE5532, 7812, 7912
Download PCB files in PDF: TDA2030 datasheet, NE5532 datasheet , Schematic of the amplifier 2.1, PCI board, component side, Silk Screen. Just remember that whoever Libraries (library) for the TDA2030 and NE5532 for the Eagle, these components are linear in the library.