Summary of Digitally Controlled 2.1 Channel Analog Audio Power Amplifier
This article presents a high-quality digitally controlled 2.1-channel analog audio power amplifier based on the TDA7377 power amplifier IC and a PIC18F452 8-bit microcontroller. Designed to work with PC sound cards, radios, and CD/DVD/Blue-Ray players, it emphasizes using consistent component manufacturers, recommended soldering order, IC sockets, ribbon cables for controls, and specific wire gauges for power and I2C connections. Firmware and PIC source code (MikroC) for an 8 MHz clock are available for download from the project website.
Parts used in the Digitally Controlled 2.1 Channel Analog Audio Power Amplifier:
- TDA7377 AF power amplifier IC
- PIC18F452 8-bit microcontroller
- IC5 - 7805 voltage regulator
- IC6 - 7808 voltage regulator
- Capacitors (various values)
- Resistors (various values)
- IC sockets for DIP and TDA7377 ICs
- Jumper wires
- Ribbon cables for control and display lines
- 18-20 gauge multi-strand power and output wires
- Teflon coated 32-30 gauge wires for I2C and MCU standby lines
- Display modules (connected via wires)
- Connectors/terminals for controls, I/O, and power
This article introduces high quality digitally controlled 2.1 channel analog audio power amplifier system. This project is mainly based on TDA7377 AF power amplifier and PIC18F452 8bit microcontroller. Basic technical features of this receiver are covered in table1.
This unit is specifically design to work with PC sound cards, radio receivers and CD/DVD/Blue-Ray players.
| Construction |
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This system use commonly available electronic components and substitute components can also use.
For maximum quality we recommended to use components from same manufacturer. For example some actual capacitor values and resistor values are slightly varied from manufacture to manufacturer, and this cause some minor unbalances in output of amplifiers. When soldering the PCB we suggested to soldering small components such as jumper wires, resistors first and moving to larger components at last.
Also try to use IC sockets for all the DIP and TDA7377 ICs. In our prototype all the integrated circuits except 2 voltage regulators (IC5 – 7805 and IC6 – 7808) are connected to mainboard via IC sockets. All the controls, I/O and power terminals and display modules are connected to mainboard through wires, and for control and display lines we recommended to use suitable ribbon cables. For power and output wires 18-20 gauge multi-strand cables are recommended (these wires are commonly used for automotive wirings). In given PCB design 4 wires need to be installed for I2C bus and MCU STAND-BY lines. For this, standard Teflon coated 32-30 gauge wires are sufficient.
| Microcontroller firmware and source code |
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This project is an open hardware project and all the source codes of PIC18F452 MCU are available to download at project website. The source code of PIC18F452 is written using MikroC for PIC compiler and free version of this compiler is available to download at Mikroelektronika[1] home page. Currently available firmware is design for 8MHz clock and other required MCU related settings are listed in table 2. Compiled HEX file for PIC18F452 is also available to download at project website.
For more detail: Digitally Controlled 2.1 Channel Analog Audio Power Amplifier
- What are the main ICs used in this amplifier project?
The main ICs are the TDA7377 AF power amplifier and the PIC18F452 microcontroller; two voltage regulators 7805 and 7808 are also used. - Can this unit be used with PC sound cards and CD/DVD players?
Yes, the unit is specifically designed to work with PC sound cards, radio receivers, and CD/DVD/Blue-Ray players. - Are the microcontroller source code and firmware available?
Yes, all PIC18F452 source code and compiled HEX file are available to download at the project website. - What compiler was used for the PIC18F452 source code?
The source code is written using the MikroC for PIC compiler and the free version is available from Mikroelektronika. - What clock frequency is the firmware designed for?
The currently available firmware is designed for an 8 MHz clock. - What wiring is recommended for power and outputs?
18-20 gauge multi-strand cables are recommended for power and output wires. - What wiring is recommended for I2C bus and MCU standby lines?
Standard Teflon coated 32-30 gauge wires are sufficient for the I2C bus and MCU standby lines. - Should IC sockets be used for the integrated circuits?
Yes, the article suggests using IC sockets for all DIP and TDA7377 ICs; in the prototype all ICs except the two regulators are socketed. - Is it important to use components from the same manufacturer?
Yes, for maximum quality the article recommends using components from the same manufacturer to avoid minor unbalances in amplifier outputs. - What is the suggested soldering order when assembling the PCB?
Solder small components such as jumper wires and resistors first, then move to larger components last.
