Dilshan R Jayakody’s Web Log

This is high quality audio power amplifier which we constructed for our audio related experiments. This amplifier is based on NXP’s TDA1521A integrated circuit and it is capable to deliver 2 × 6W audio output power with 20V - 25V asymmetrical power source. The design of this power amplifier is heavily based on the schematic provided in the TDA1521A datasheet. As an addition we incorporate headphone output option to this design. Connection diagram for TDA1521A Amplifier PCB PCB which we designed for this amplifier is 55mm × 65mm and it need separate power supply to drive. For optimal results use this AF amplifier with 12V – 20V regulated DC supply and with 4 Ω full range speaker pair. PCB, schematic and wiring diagram of this project is available to download at google drive .

Smart Audio Box (SAB) is microprocessor controlled audio switch and amplifier system, which is specifically design for audio composers and for audio engineers. SAB consist of 4 high impedance stereo inputs and two output modes. One output mode can drive stereo headphone/earphone and other output mode can drive pair of 8W speakers. In prototyping stages we identify those modes as " Personal Mode " (headphone output) and " Audience Mode " (power amplifier output). Another main feature of this system is its programmable 16 step attenuation controller. This attenuation controller helps to control the audio output level of each output-mode. Prototyping version of Smart Audio Box The main component of SAB system is ATmega8 MCU, other than that headphone amplifier is design around NJM4556 high current operational amplifier and power amplifier is based on TDA1521A. To operate, this system requires 2 power sources. Microcontroller, ADC interfaces and CMOS logic-s...