prolem chipamp TDA7294

vthieu

Member
2005-10-15 7:46 am
Hi !every body
I first DIY Chipamp with this application schema TDA7294,but the output in pin 14 have 4Vdc. It make the sound very bad . I change 2 chip TDA but nothing . Any one have ideal help me please!
Because I hear TDA7294 very easy to make with some little component and very easy suscessful. Hu hu
[IMGDEAD]http://www.flickr.com/photos/[email protected]/2212069488/[/IMGDEAD]
:(
 

ashok

Member
2002-06-06 4:43 am
3RS
Check your circuit again . Take a break and look at it after a couple of days. Sometimes you overlook obvious mistakes if you keep spending too much time on it.

The application circuit works very well.
Search for 'TDA7294' on this forum. You will find lots of informatioin and 'warnings'.
 

vthieu

Member
2005-10-15 7:46 am
Many thank for your ideal !
I will check it again on another day , when I refesh!But I no found mistake in PCB with little component , what can I do ?
R (in+) pin 3 =22k
R (in-)=680
R link speaker- (in-) = 22K
 

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ashok

Member
2002-06-06 4:43 am
3RS
Remove C2 and C5 . Leave the terminal open ( do not short the terminals ). If the problem goes away then you had a wrongly connected capacitor.
I suspect wrong polarity in C5 but I could be wrong.
If you still have a problem, check the supply pins for proper voltage . What voltages are you using in the power supply?

C3 and C4 are connected with -Ve terminal to ground ?
 

vthieu

Member
2005-10-15 7:46 am
C5 : + link spker
- link pin6
C2 : + link pin2
- link GND
Please tell me if I change C5 = 47uF or 100uF what happen?
it still wrong , 4Vdc in pin14?
Vs- = -28 Vdc
Vs+ = +28Vdc
C6&C8 cap for Supply . I think if i wrong conect polary cap -> BUM BUM.But it OK ,I think ghost could be in my PCB.