4 X 15 Watt power amplifier

jacky April 7, 2010 10 Comments

Description.
A lot of electronic circuits in the domain of audio amplifiers are already been published here. This circuit is a little different because it is a four channel amplifier. Each channel of this amplifier can deliver an output of 15Watts into a 4 ohm speaker. The amplifier can be operated from a single 12V DC supply and this makes it possible to use this amplifier in car audio applications too.

The circuit is based on the 15W BTL X 2 channel audio power amplifier IC TA8215 from Toshiba. Even though chip is specifically designed for car audio applications it can be also used for home audio applications. Two TA8215 ICs are used here in order to obtain a 4 channel amplifier system. The circuit is designed almost exactly as per the application diagram in the ICs datasheet. Pins 7 and 19 are the Vcc pins of the ICs internal integrated power amplifier stages and these pins are connected to the positive supply. Pin 9 is the Vcc pin for ICs internal preamplifier and it is also connected to the positive supply. Pins 13 and 14 are the internal power amplifiers ground pins and they are tied together and connected to the ground. The internal preamplifier’s ground pin (pin5) is connected to the common ground through a 10 Ohm resistor which makes the input ground separated from the common ground by a resistance of 10 ohms and this improves the noise rejection. The 100uF capacitor works as a power supply de-coupler. The resistor networks connected to the output lines of each amplifier improves the high frequency stability. The variable resistors (R3, R4, R12 and R13) works as the volume controller for the corresponding channels.

Circuit diagram.

4X15W amplifier circuit

Notes.

  • Assembling the circuit on a good quality PCB is a must for obtaining optimum sound quality.
  • Use 12V DC for powering the circuit.
  • The ICs must be fitted with adequately sized heat sinks.
  • R3, R4, R12 and R13 serves as volume controllers.
  • K1 to K4 can be 4 Ohm, 20W speakers.
  • This amplifier circuit can be used in a variety of applications such as car audio systems, home theater systems, personal audio systems, public address systems etc.

Comments
  • krishna
    August 10, 2012

    in circuit pin no 7 is connected to both vcc & ch 2 input, is this write?
    what about the pin no 1 & 17?

  • תוכנית שותפים
    August 6, 2012

    I have been exploring for a bit for any high quality articles or blog posts on this sort of area . Exploring in Yahoo I at last stumbled upon this site. Reading this info So i’m happy to convey that I have a very good uncanny feeling I discovered just what I needed. I most certainly will make certain to don’t forget this web site and give it a look on a constant basis.

  • Krishna
    October 15, 2011

    thanks a lot, i have successively completed it. Once again thanks for ur support

  • seetharaman
    October 11, 2011

    Hi Krishna the front face of the IC is having the type number etc. the rear side metal plate (this is called the heat tab)is for conducting the heat. this is to be thermally connected to a good quality heat sink by applying silicon conductive paste in the conductive area.

  • Krishna
    October 7, 2011

    Thanku seetharaman sir.
    But what about the ‘TAB’ pin, where is it?

  • Zeeshan
    September 28, 2011

    Hi guys,
    I have 15watts speaker x2 (4 ohms each). The amplifier in those speakers isnt working, broke probably. Can u plz guide me how can i make amplifier for my speakers. It would be best if i could use TDA2616 IC, i have 2 of these right now.
    Any help would be much appreciated.

  • seetharaman
    August 31, 2011

    Hi Krishna it is called the Zobel network, can be any value between 0.1 to 0.47uF.
    Front side of the IC will have its model number and the rear side of the IC has metal surface that is to be thermally connected to a suitable heat sink.

  • Krishna
    August 31, 2011

    sir i have some questions.
    1.where is the “tab” pin located, or where is it connected to??

    2. since 150nf is unavailable i m using (100 + 47) nf cap, sound output is not good. can i do that????

  • Jonathan
    March 5, 2011

    Apparently, they are rheostats!

  • pitong
    March 8, 2010

    how are you going to control the signal if R3,R4,R12 &R13 POTS’ center tap is not connected?

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