Many electronic audio amplifier circuit has been published here. This time, we use the TDA 1514 high performance hi-fi amplifier from Philips.
The IC has many useful features such as thermal protection, Mute / stand-by facilities, low harmonic distortion, etc. This amplifier operates from dual power supply +25 / -25 V DC and can deliver output power of 40Watts into an 8 ohm speaker.
Amplified audio signal is is given to pin 1 of The IC and the capacitor C2 acts as a DC-coupling. Resistors R3 and R4 determine the closed loop gain and can vary between 20 and 64 dB. Resistor R2 and capacitor C4 provides the correct impedance speaker Zobel network and improve frequency response. Resistors R7, R6 and capacitor C5 are boot strap components. If the boot strapping is not required then these components can be removed and PIN7 can be connected to pin 6, but power output will be reduced by about 10%. R1 is the input resistance and bias that has an effect on input impedance.
Parts list :
R1, R3 : 20K
R2 : 3.3 ohm
R4 : 680 ohm
R5 : 470K
R6 : 150 ohm
R7 : 82 ohm
C1 : 220pF
C2 : 1uF
C3 : 3.3uF
C4 : 22nF
C5 : 220uF
C6 : 0.47uF
C7 : 47uF
C8 : 0.47uF poly
IC1 : TDA1514A
Notes :
Assemble the circuit on good quality printed circuit will improve sound quality.
Use a 25 /-25V DC, 4A power supply to power the dual circuit.
K1 can be an 8 ohm, 50W speaker.
IC1 must be equipped with an appropriate heat sink
