Hi,
I just made a TDA2003 amp for my PC. I set the gain resistors at 4.7 ohm and 220 ohm. When I plug in the audio source, there is too much distortion that the actual music can barely be heard. I am running it from a 12v 4a power source i built myself.
What could be the reason for the distortion? What can I do to remove it?
I thank you in advance for any help i can get.
I just made a TDA2003 amp for my PC. I set the gain resistors at 4.7 ohm and 220 ohm. When I plug in the audio source, there is too much distortion that the actual music can barely be heard. I am running it from a 12v 4a power source i built myself.
What could be the reason for the distortion? What can I do to remove it?
I thank you in advance for any help i can get.
why did you not use the circuit in the application notes?
http://pdf1.alldatasheet.com/datasheet-pdf/view/25035/STMICROELECTRONICS/TDA2003.html
Andy
http://pdf1.alldatasheet.com/datasheet-pdf/view/25035/STMICROELECTRONICS/TDA2003.html
Andy
Tahmid said:
Remove the C3 0.22u capacitor form output to GND.
Replace C8 0.22u, now across speaker output,
with one Capacitor 100nF + 1 Ohm in series, across speaker output.
Like C5 + R3 in my attached example from TDA2003 datasheet.
Datasheet TDA2003:
http://www.st.com/stonline/products/literature/ds/1449.pdf
Attachments
The gain is too much high.... if i can remember the gain is the division of two
resistances.... and you have 220 and 4.7 ohms... this seems to me your gain will be 47.
Your PC output signal goes to 1 volt.... with your gain will distort...the maximum output power is obtained with 4 volts output (more or less)..... so....you have to multiply (gain) your PC signal by a ratio of four... and not 47.... your resistances must be 220 ohms and 56 ohms, or 220 ohms and 47 ohms.
This is your problem.... with 1 volt entering (alternated volts, audio volts) your circuit is trying to produce 47 volts...and this is not possible..so... too much gain means enormous distortion.
The problem is just this one...... i can be wrong about those resistances, but for sure the gain has some preset alike that one.
Search for datasheet and check your gain.... adjust it to 4 or 5....not more than that.
regards,
Carlos
resistances.... and you have 220 and 4.7 ohms... this seems to me your gain will be 47.
Your PC output signal goes to 1 volt.... with your gain will distort...the maximum output power is obtained with 4 volts output (more or less)..... so....you have to multiply (gain) your PC signal by a ratio of four... and not 47.... your resistances must be 220 ohms and 56 ohms, or 220 ohms and 47 ohms.
This is your problem.... with 1 volt entering (alternated volts, audio volts) your circuit is trying to produce 47 volts...and this is not possible..so... too much gain means enormous distortion.
The problem is just this one...... i can be wrong about those resistances, but for sure the gain has some preset alike that one.
Search for datasheet and check your gain.... adjust it to 4 or 5....not more than that.
regards,
Carlos
TDA2002/2/4/5 have a really nasty habit of oscillating. Because the input is referenced to the same ground pin that carries high current, it's way too easy to have a bad layout. Not only do you need a star ground, but the resistance/inductance from the ground pin to the star ground needs to be minimized. If the chip gets hot just idling, then this is what's going on here. The output shunt cap does need a damping resistor, and it needs and ohm or two (not the usual 10 ohms). And be very careful where you "ground" it.
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