Hey guys! How can I eliminate this annoying static buzz from my tweeters?
I'm using a tpa3116 amp, its probably Chinese. I don't have any audio signals connected to it. I'm using a power supply (24V, 6.25A).
How could I stop the buzz? or just reduce it?
I'm using a tpa3116 amp, its probably Chinese. I don't have any audio signals connected to it. I'm using a power supply (24V, 6.25A).
How could I stop the buzz? or just reduce it?
What type of power supply are you using? Linear/Switching? Quality/$10 junk?
I'm fairly new to this, but Class D amplifiers seem fairly sensitive to power supply noise. Supposedly it's intermodulation between the PSU switching frequency and the amplifier switching frequency. Add a 10uF electrolytic along across positive rail and ground anywhere you like. Also add a 100nF and a 220pF capacitor across the supply rails for every chip. These have to be as close to the chips as possible.
I don't know what the input path looks like on your amplifier, but I added a 10k resistor i series with the input and a 220pF capacitor to ground after the resistor. That got rid of a lot of switching noise making its way back to the input.
To rule out the power supply and if you have a powerful enough battery, try powering it from a battery, since that's a very clean power source. If that gets rid of the noise, it's the power supply and you need to sprinkle capacitors across the rails. If the noise persists, you have switching noise backfeeding to the inputs circuitry. Add passive RC filters where needed.
I'm fairly new to this, but Class D amplifiers seem fairly sensitive to power supply noise. Supposedly it's intermodulation between the PSU switching frequency and the amplifier switching frequency. Add a 10uF electrolytic along across positive rail and ground anywhere you like. Also add a 100nF and a 220pF capacitor across the supply rails for every chip. These have to be as close to the chips as possible.
I don't know what the input path looks like on your amplifier, but I added a 10k resistor i series with the input and a 220pF capacitor to ground after the resistor. That got rid of a lot of switching noise making its way back to the input.
To rule out the power supply and if you have a powerful enough battery, try powering it from a battery, since that's a very clean power source. If that gets rid of the noise, it's the power supply and you need to sprinkle capacitors across the rails. If the noise persists, you have switching noise backfeeding to the inputs circuitry. Add passive RC filters where needed.
sounds like hum buzz when you touch an input pin with a finger. Most of the TPA 3116 chip amps are made with too much gain. Short the input to ground, is the noise gone? Are all of your input wires properly grounded and shielded? There are many posts on this web site on how to lower the gain. Try adding a low value resistor 100 ohms to 1 K ohms across the input to ground, does the noise go away? What is your source of music? computer, phone, tablet, bluetooth? I had an old tablet and I could easily hear my fingers moving across the screen. Many of the bluetooth + 3116 boards are very noisy. Does the TPA3116 board have a volume control? I was fighting a noise problem when I finally found the problem it was a compact florescent lamp.
What multisynch is saying is important. Check the sources first! I was just troubleshooting my homemade from scratch Class D like a madman and it turned out that the source was faulty. Apparently, when the CPU on my laptop gets overloaded it introduces what sounds exactly like static.