OK. I expected it to be better with 12V.
One thing I notice from the video is that the cores in the output filter chokes are yellow. I have tried such chokes myself and they worked poorly. The reason is that the cores used for the chokes are made with a ferrite (marked with this yellow/greeninsh color) that cannot handle the 400KHz used as the carrier frequency for the TPA3116. While the chokes will have the right inductance measured at a lower frequency, the inductance at 400Khz will be significantly lower such that circulating currents from the carrier will be much higher than they should be. My impression is that the amplifier in the video is current overloaded and what you observe is the current protection repeatedly switching the amplifier off, then re-starts the amplifier just to realize that the over-current remain.
Do the chokes become warm during this strange operation?
One thing I notice from the video is that the cores in the output filter chokes are yellow. I have tried such chokes myself and they worked poorly. The reason is that the cores used for the chokes are made with a ferrite (marked with this yellow/greeninsh color) that cannot handle the 400KHz used as the carrier frequency for the TPA3116. While the chokes will have the right inductance measured at a lower frequency, the inductance at 400Khz will be significantly lower such that circulating currents from the carrier will be much higher than they should be. My impression is that the amplifier in the video is current overloaded and what you observe is the current protection repeatedly switching the amplifier off, then re-starts the amplifier just to realize that the over-current remain.
Do the chokes become warm during this strange operation?
This is one likely problem. Unfortunately there may be other.
Do you have access to an oscilloscope? Do you have access to replacement parts for test?
Do you have access to an oscilloscope? Do you have access to replacement parts for test?
I don't have oscilloscope. I can buy replacement parts, it's not expensive but I don't know which one.
I saw somewhere that the chokes are 10microH 5A.
I saw somewhere that the chokes are 10microH 5A.
10uH/5A is fine as such. The problem is very likely that this type of ferrite is suited for 50KHz but not 400KHz. I made the same mistake because there was no information about the ferrite.
Your amplifier will need some re-work. How much time and cost for replacement parts will you invest? Can you still claim money back from the seller?
No, I can't. I was thinking to repair by myself or throw in the trash. I can give about 10$ for replacement parts, because i can buy another one for 18$, but shipping is to long so I want to try to repair that.
Do you have a multi-meter (for measuring voltage and impedance)? Do you have a soldering iron? Do you have an old speaker you can use for tests that you are ready to loose?
Fine. A clear problem is in the amplifier output filters. The chokes seem to prevent the amplifier chips from operating. To see if the rest of the amplifier circuit works, you need to disconnect all 6 filter chokes from the TPA3116 chips. That you do by de-soldering all 6 filter chokes and remove them from the board.
Ok, that's easy. If it's works can I leave amplifier without chokes but not amplify sound to much because of bigger current?
TPA3116 can work without a real output filter for test. If the rest of the amplifier seems to work, we can look for new filter chokes. We need to get down to a configuration that functions and then re-build the amplifier to work in full.
When the chokes have been removed, you need to find a good long piece of two-wire cable like the type you use for lamps etc.
You connect your cheap test speaker in one end of the cable and connect the other end of the cable to the TPA3116 chip outputs, one set of (two) output lines at a time. The long cable will work as an output filter temporarily. Then we have to measure if the DC-offset for each set of output lines is correct before testing with music.
Use your 12V/1000mA power supply for all tests.
Let me know when you have removed the chokes and is ready to continue. We won't finish tonight.
True, to do with an old wide-band speaker. The way to progress when you doubt your output filter. And, not to be used with max. volume.
hi guys, got this board, bluetooth chip is dead short so i removed it, now i put signal to the bypass input so i can use aux or rca but tpa3116 will not output unless i inject 1.8v to the bt out 1v8 pin, anyway i can bypass this?
Actually in a PWM system volume doesn't change what comes out the outputs, they're always running flat out, almost rail to rail. What changes, and what the filter reacts to is the change in the width of the pulses.