Distortion in sound on TPA3116d2

digitaled

Member
2018-09-20 11:39 am
Hi again..

I'm using the TPA3116d2 board in my car with the 12 volt power and few days back I posted about that also.

I have noticed another problem which is not a big one but still I thought to find out why it's happening here from the experts.

Whenever I increase the volume more than 70% the sound get bit distorted it's not too much of distortion but I could clearly hear some muffling sort of sound in the vocals and once this distortion starts even if I decrease the volume it remains there.

The only way to get rid of that sort of muffling or distorted sound is to turn off the amplifier and then restarted connect again to the bluetooth device and keep it below 70%.

One more thing the volume from the amplifier controller knob is full. As I have connected my phone to it when I increase the volume from phone and when it goes beyond 70% from phone sound level it begins to distort.

I even thought that it might be too much of bass that's doing it but I lowered the bass level and the distortion especially in the vocal was still there.

It's not much a problem as I usually dont play that loud but once a while when I try the distortion ruins the clarity of sound and I have to then restart the amp.

Can anyone please tell me why such thing happens and just to clear the sound from 0 to 80% remains fine but whenever it goes from 80 % above even a little bit of it the sound gets distorted.

Any help on this.. please thanks
 
It seems to me the amp is defective. It can be unstable feedback loop (not giving enough phase margin to prevent oscilations), but I think TPA3116D2 works without feedback (not an expert there). In that case I would shift focus on the components that can break reversible: MOSFETs, opamps, TPA chip itself or - more frequently - self healing capacitors. You should check all electrolytic, tantalum, polymer based aluminium and metalised film capacitors in the feedback and power output path (this is a place the maximum voltage depends on the volume).

Self-healing film cap types are polypropylene (PP) and polyphenylene sulfide (PPS). Permanent reduced capacity and increased ESR is result in repeated breakdown. In some cases it can be tested in-circuit, but typically it requires replacing.
 
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12 volt is a very low voltage power supply.
This amp will give about 18 Watt max. at 4 ohm with it.
If you dial in some bass (or activate loudness) it will clip even at moderate listening level. The voltage may dip and some protection will engage. To reset you have (with some protection circuits) to cycle the PS. Usually they should reset by them self, but if voltage is to low, this may not always work.

If you need more power, increase the voltage to 24 volt by some switching power supply for car use. For the usual 3116 amp, 5 ampere should be plenty.
 

digitaled

Member
2018-09-20 11:39 am
Thanks for the replies esp the Victorian reply..good one..

I will try with atleast 19v power and will update the performance here in few days as I am going to order now.

👍👍


Hi,
the first thing that comes to mind is that you drove a too low Z load

like two pairs of 4Ω speakers . If you find two paralleled speakers ( front, rear) per channel, try to disconnect one

12 volt is a very low voltage power supply.
This amp will give about 18 Watt max. at 4 ohm with it.
If you dial in some bass (or activate loudness) it will clip even at moderate listening level. The voltage may dip and some protection will engage. To reset you have (with some protection circuits) to cycle the PS. Usually they should reset by them self, but if voltage is to low, this may not always work.

If you need more power, increase the voltage to 24 volt by some switching power supply for car use. For the usual 3116 amp, 5 ampere should be plenty.
 

digitaled

Member
2018-09-20 11:39 am
Last edited:

digitaled

Member
2018-09-20 11:39 am
Can anyone recommend what kind of power converter is available for cars.

12v to 19-24v

TIA.





Hi,
the first thing that comes to mind is that you drove a too low Z load

like two pairs of 4Ω speakers . If you find two paralleled speakers ( front, rear) per channel, try to disconnect one

It seems to me the amp is defective. It can be unstable feedback loop (not giving enough phase margin to prevent oscilations), but I think TPA3116D2 works without feedback (not an expert there). In that case I would shift focus on the components that can break reversible: MOSFETs, opamps, TPA chip itself or - more frequently - self healing capacitors. You should check all electrolytic, tantalum, polymer based aluminium and metalised film capacitors in the feedback and power output path (this is a place the maximum voltage depends on the volume).

Self-healing film cap types are polypropylene (PP) and polyphenylene sulfide (PPS). Permanent reduced capacity and increased ESR is result in repeated breakdown. In some cases it can be tested in-circuit, but typically it requires replacing.

12 volt is a very low voltage power supply.
This amp will give about 18 Watt max. at 4 ohm with it.
If you dial in some bass (or activate loudness) it will clip even at moderate listening level. The voltage may dip and some protection will engage. To reset you have (with some protection circuits) to cycle the PS. Usually they should reset by them self, but if voltage is to low, this may not always work.

If you need more power, increase the voltage to 24 volt by some switching power supply for car use. For the usual 3116 amp, 5 ampere should be plenty.

Thanks for the replies esp the Victorian reply..good one..

I will try with atleast 19v power and will update the performance here in few days as I am going to order now.

👍👍