Finally build a complete amplifier using TAS5261 & TPA3122.
Amp sounds good at low input levels but strongly clips when the input to 3122 is increased.
As I dont have access to an osciloscope, I am unable to find the problem.
can anybody sugget.
I can post the schematic too if any body is intrested.
Thanks
Amp sounds good at low input levels but strongly clips when the input to 3122 is increased.
As I dont have access to an osciloscope, I am unable to find the problem.
can anybody sugget.
I can post the schematic too if any body is intrested.
Thanks
heres a pic of the underside...
note: i tried a few things to fix the problem already, including adding morewire accross the power lines (to decrease resistance) and tried adding a much more capacitance to the power input in case the problem had something to do with supply pumping. Also tried swaping one of the speaker outputs terminals in case of that too (as mentioned in the datasheet).
really curious what's causing this...maybe it has something to do with the input cap at 1uf? I noticed when the gain setting is on high the input resistance changes and thus the input cap value should differ...but I'm not sure to what and how/if that would cause clipping.
any ideas anyone?
many thanks in advance...
note: i tried a few things to fix the problem already, including adding morewire accross the power lines (to decrease resistance) and tried adding a much more capacitance to the power input in case the problem had something to do with supply pumping. Also tried swaping one of the speaker outputs terminals in case of that too (as mentioned in the datasheet).
really curious what's causing this...maybe it has something to do with the input cap at 1uf? I noticed when the gain setting is on high the input resistance changes and thus the input cap value should differ...but I'm not sure to what and how/if that would cause clipping.
any ideas anyone?
many thanks in advance...
Attachments
unbalanced output channel
I have apower amplifier using stk401-130 af ic that has no balance output. itry to balanced with tone control balanced. at frst results,its ok but later on my LSpeaker was burnt out. what is the possible defect? Can I have some tips about this? thank you very much for anybody.....
I have apower amplifier using stk401-130 af ic that has no balance output. itry to balanced with tone control balanced. at frst results,its ok but later on my LSpeaker was burnt out. what is the possible defect? Can I have some tips about this? thank you very much for anybody.....
Audiomodder,
It's really difficult to tell whats going on with your board, the p2p wiring makes it hard to follow what's connected to what.
I can say for sure that supply pumping is not a concern, and a low value input cap will just roll off the low end, not make the amp distort or lower the overall output level.
What's the AC voltage on the output when it starts to distort? Input signal voltage? What's the supply voltage you are using?
There's really only a few things that could be the problem, it's not really a complicated circuit. It's either a problem with the wiring, a component value/type, or the IC is damaged (though not likely).
Sorry, wish I could help out more.
It's really difficult to tell whats going on with your board, the p2p wiring makes it hard to follow what's connected to what.
I can say for sure that supply pumping is not a concern, and a low value input cap will just roll off the low end, not make the amp distort or lower the overall output level.
What's the AC voltage on the output when it starts to distort? Input signal voltage? What's the supply voltage you are using?
There's really only a few things that could be the problem, it's not really a complicated circuit. It's either a problem with the wiring, a component value/type, or the IC is damaged (though not likely).
Sorry, wish I could help out more.
Hi Audio modder,
Found good solution,
I first converted the analog audio to PCM format then from PCM to PWM
mail me at akjain2007@dataone.in to have a look at the board design & layout as the picture size is large to post
I used PCM1808 & TAS 5010.
Hope it shall help you. The distortion problem dissapeared although the power output is somewhat lesser.
I shall update you very soon.
Found good solution,
I first converted the analog audio to PCM format then from PCM to PWM
mail me at akjain2007@dataone.in to have a look at the board design & layout as the picture size is large to post
I used PCM1808 & TAS 5010.
Hope it shall help you. The distortion problem dissapeared although the power output is somewhat lesser.
I shall update you very soon.
thanks for the replies all 
Jash, the 100nf caps are the small yellow ones closest to the top and bottom of the amp.
What do you mean by PCM and PVM conversion? I am not familiar with this. Shouldn't the amp just work with an MP3 player or computer audio plugged in??
I'll check the AC output and voltage input soon... the supply voltage is 24v but the problem happens with 12v input too I believe.
Jash, the 100nf caps are the small yellow ones closest to the top and bottom of the amp.
What do you mean by PCM and PVM conversion? I am not familiar with this. Shouldn't the amp just work with an MP3 player or computer audio plugged in??
I'll check the AC output and voltage input soon... the supply voltage is 24v but the problem happens with 12v input too I believe.
hey everyone,
sorry to report back so late, my last chip died so I had to order some new ones and redo a lot of the project.
I ordered new parts for every component all rated at 50v and ceramic this time to avoid polarity issues (not that I really had those before).
The amp still has the same problem BUT it only does this on 24v now, seems to run perfect on 12v.
The reason I found my chips kept blowing before is I had a bad 24v supply (I have 2) the bad one I am of course not using anymore. The bad one was somehow damaging the input caps but without making them blow(?) very strange. Anyway this problem is remedied and there is a new chip now but still clipping.
I measured the AC voltage on output at clipping and it's a little hard to grab since it oscillates extremely fast (<1sec) but I found that in normal operation AC voltage is usually <1volt, sometimes a tiny bit higher. When the clipping happens it jumps to 3.4v+ AC.
hopefully this info will be useful in finding the problem. I have 2 470uf caps close to the chip on the power lines, this should solve and power supply pumping problems (and I believe I tried more caps in the past as well). so I'm out of ideas. I took new pics of the board with the new components if anyone thinks that will help I will post those as well.
thanks,
audiomodder
sorry to report back so late, my last chip died so I had to order some new ones and redo a lot of the project.
I ordered new parts for every component all rated at 50v and ceramic this time to avoid polarity issues (not that I really had those before).
The amp still has the same problem BUT it only does this on 24v now, seems to run perfect on 12v.
The reason I found my chips kept blowing before is I had a bad 24v supply (I have 2) the bad one I am of course not using anymore. The bad one was somehow damaging the input caps but without making them blow(?) very strange. Anyway this problem is remedied and there is a new chip now but still clipping.
I measured the AC voltage on output at clipping and it's a little hard to grab since it oscillates extremely fast (<1sec) but I found that in normal operation AC voltage is usually <1volt, sometimes a tiny bit higher. When the clipping happens it jumps to 3.4v+ AC.
hopefully this info will be useful in finding the problem. I have 2 470uf caps close to the chip on the power lines, this should solve and power supply pumping problems (and I believe I tried more caps in the past as well). so I'm out of ideas. I took new pics of the board with the new components if anyone thinks that will help I will post those as well.
thanks,
audiomodder
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