I have one of those red PAM8403 amplifiers. When I connect my PWM audio output from Arduino to it, it's like it played the sound reaaaally slowly because I hear multiple individual "clicks" per second. The only way to avoid it is connecting the Audio in to a 100uF capacitor before going to the amplifier. Bigger or smaller capacitors doesn't solve the clicking sound.
I have another amplifier from my speakers, also made with a PAM8403 on a green board. This one has a big through-hole capacitor of 1000uF iirc, and doesn't sound like that.
So the question is: my amplifier is fried? I also see that one of the capacitors on the red board has two holes, should I connect another parallel capacitor there?
The only way to avoid it is connecting the Audio in to a 100uF capacitor before going to the amplifier.
Does that mean a series capacitor or a parallel one?
It looks like C1 and C2 are series input capacitors.
It also looks like C8 was designed for a large capacitor and someone put a small one there, maybe to save money. I would try connecting something big to that.
In general amplifiers like this need a big supply decoupling capacitor, that is between power and ground, the bigger the better.
Grumpy_Mike:
Does that mean a series capacitor or a parallel one?
Series: PWM out (from Arduino) -> capacitor+ -> capacitor- -> R+ on the amp.
Any suggested capacitor for decoupling? Maybe the big one on the PC speakers are for that (they're USB speakers btw).
Any suggested capacitor for decoupling?
1000uF
they're USB speakers btw
Not too sure what that means. Most of the speakers I have that plug into the USB only do so for the power so the term USB speaker is a bit of an anachronism.
Means simply that, they're usb powered.
