Hello, I recently bought a really quite nice sounding Amplifier of amazon. It sounds great for the price, but as soon as I turn the volume up to max, it starts cutting in and out.
My setup:
2*60W 4ohm speaker
1*150w 4 ohm subwoofer
I'm going to take a guess that some sort of protection system is kicking in. It says it has overvoltage, undervoltage, overheat and "DC detection". It's not overheating, I measured the 19v power supply s output voltage and it stayed constant. So the only thing it could be is DC Detection.
Is the duty cycle going too high on the output??
I would be really grateful for any help 🙏
My setup:
2*60W 4ohm speaker
1*150w 4 ohm subwoofer
I'm going to take a guess that some sort of protection system is kicking in. It says it has overvoltage, undervoltage, overheat and "DC detection". It's not overheating, I measured the 19v power supply s output voltage and it stayed constant. So the only thing it could be is DC Detection.
Is the duty cycle going too high on the output??
I would be really grateful for any help 🙏
You can easily measure how much DC you have at the output terminals of each speaker. In the photo there are the limits of the 3116 or 3126 chip (I discovered that I have the latter), values vary after power on, take more measurements while using. A load "pop" when you turn on the amplifier, I think it indicates the presence of DC towards the speakers (I solved it by arranging the capacitors on the audio inputs)
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ok so i disconnected the subwoofer from the amp, and i can now play as loud as possible. the subwoofer is 4 ohms so i dont see the issue, turns out its rated at 90W, still should be fine...
All 3 channels will have about the same power into 4 ohm speakers. The subamp protection tripping could have several causes. 1 find out if subamp is working properly🙂 The subampchip is connected as slave looking at the synch parts under the heatsink, the little capacitor might be too large a value, causing erratic behavior of the slave subamp chip.
2nd. Opamps might amplify the inputsignal and maybe the additional volumecontrol for sub means you oversteer the input of the subchip, it depends on gainsetting too. It looks you have a mainvolume and a subvolume, remember the maximum output of all channels is about the same!
2nd. Opamps might amplify the inputsignal and maybe the additional volumecontrol for sub means you oversteer the input of the subchip, it depends on gainsetting too. It looks you have a mainvolume and a subvolume, remember the maximum output of all channels is about the same!
If you have a stable 19V from the power supply with all speakers in use, I think you have no power problem.
Maybe DC detect could be the problem. I'd start with just measuring the DC at the speaker outputs; from a few initial volts, with the repair I went down to 0.4vdc and the "pop" on power up and the amp shut-down are gone. The presence of DC volts at the speaker outputs is resolved by replacing the cap on the inputs of the 3116 (or other chip). Of course, some skill is required to replace SMT cap.
No caps on the audio outputs needed! ;-)
Input cap 3116 issue
Hi everyone, I had a similar issue, where the volume would get pretty loud and then it would cut out, it was going into protection mode. I checked everything until I found the problem, and reducing the treble fixed the issue. Notably, I later checked the tweeters and they were damaged, so the protection was kicking in because my tweeters were blown.
My setup
Zktb21 (TPA3116D2)
2X 40 W RMS - 4 OHMS - 2 WAYS (4")
1X 90 W RMS - 2 OHMS - MID-SUBWOOFER (30-1000 HZ) (6.5")
My setup
Zktb21 (TPA3116D2)
2X 40 W RMS - 4 OHMS - 2 WAYS (4")
1X 90 W RMS - 2 OHMS - MID-SUBWOOFER (30-1000 HZ) (6.5")