TDA2009A Hi-Fi audio amplifier not producing output

Thread Starter

bhaskarauvsp

Joined Jun 28, 2015
4
Dear Members,
I built a new TDA2009A Hi-Fi audio amplifier for 5.1 surround system. I prepared three TDA2009A PCB boards for driving 6 speakers. Each board is supplied by individual power supply made of 30V step-down transformer, KBP206G bridge rectifier, 2nos. of 2200MicroF capacitors in parallel, L7824CT 24V positive voltage regulator. And also attaching schematic diagram for your reference and this is different from PCB layout shown in TDA2009A datasheet. Now the problem is that sometimes i am getting output from single channel and most of the time I am not getting output from amplifier boards. Please look into the schematic and provide your suggestions and i spent lot of time to debug the circuit but in vain not able to get the sound from amplifier boards. Also note that complete circuit is made by me due to this circuit is not functioning properly.

Thanks.
Bhaskar
 

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GopherT

Joined Nov 23, 2012
8,009
What is your 5.1 audio input source? Is it already separated into 5 channels? If not, you need a device that can do that. Also, your schematic is impossible to read. Take a picture directly above and keep the camera very steady and use your flash.
 

Alec_t

Joined Sep 17, 2013
14,313
Welcome to AAC!
Your schematic is too small to see all the details. We need a larger image (but preferably similar file size).
 

bertus

Joined Apr 5, 2008
22,277
Hello,

Your drawing is not clear to me.
The feedback lines are not completed.

Have a look at the example schematic from the datasheet:

TDA2009_example_schematic.png

I have also attached the full datasheet.
It also contains a PCB for this circuit.

Bertus
 

Attachments

Thread Starter

bhaskarauvsp

Joined Jun 28, 2015
4
Hello,

Your drawing is not clear to me.
The feedback lines are not completed.

Have a look at the example schematic from the datasheet:

View attachment 87769

I have also attached the full datasheet.
It also contains a PCB for this circuit.

Bertus
Dear Members,
Please find the clear schematic and in PCB those feedback lines are already connected but same is not shown in schematic. IMG_20150629_230200_1.png
 

bertus

Joined Apr 5, 2008
22,277
Hello,

What kind of speakers do you use?
Are those 4Ω or 8Ω types?

Keep in mind that the efficiency is about 60 % at 24 Volts supply.
It can well be that the 24 Volts regulator shuts down due to overload.
You could try to replace the regulator by an 78S24, wich can deliver 2A continu and 3 A peak.
Cooling of the regulator is essential.

Bertus
 

Attachments

Thread Starter

bhaskarauvsp

Joined Jun 28, 2015
4
Hello,

What kind of speakers do you use?
Are those 4Ω or 8Ω types?

Keep in mind that the efficiency is about 60 % at 24 Volts supply.
It can well be that the 24 Volts regulator shuts down due to overload.
You could try to replace the regulator by an 78S24, wich can deliver 2A continu and 3 A peak.
Cooling of the regulator is essential.

Bertus
I am using 4 Ohm speaker at the output. There is no problem with 24V regulator because when I check the output of DC it is showing perfect 23.6V but there is no output at amplifier.
 

Thread Starter

bhaskarauvsp

Joined Jun 28, 2015
4
Near the top right corner of your schematic there is a missing connection from the negative of the supply.
Disconnection in schematic is for testing purpose only and in actual PCB it was shorted. Please provide the alternate solutions because I am unable to proceed further without knowing the actual problem.
 
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