Well that frequency is there with no signal at the audio input. If i plug in an 80HZ signal, then the frequency on the scope will change to 80HZ, but will still be noisy...
In these amps, that signal is sometimes present, sometimes not.
I wouldn't worry about the noise. It's likely from a difference in ground. Get the amp working and then if it has a noise that's going to be audible through a subwoofer, you can troubleshoot it. It's common for self-oscillating car amps to have a low level noise due to no synchronization between the power supply and audio oscillators. IT sounds like this:
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
I wouldn't worry about the noise. It's likely from a difference in ground. Get the amp working and then if it has a noise that's going to be audible through a subwoofer, you can troubleshoot it. It's common for self-oscillating car amps to have a low level noise due to no synchronization between the power supply and audio oscillators. IT sounds like this:
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
Hi again,
Finally the amp is back to life, working for the last few days without problems in my car.
Thank you very much Perry for you help!
From my last post what i did was to remove headers (i don't recommend them) , replace both drive ICs (as i burned them by mistake, trying to fix a bad soldering, but i didn't wait for the voltage to fully drain), and put everything back together. The noise in the signal seems to be from my scope grounding, so that is not audible in the speaker at all...
THANK YOU very much again!!!
Finally the amp is back to life, working for the last few days without problems in my car.
Thank you very much Perry for you help!
From my last post what i did was to remove headers (i don't recommend them) , replace both drive ICs (as i burned them by mistake, trying to fix a bad soldering, but i didn't wait for the voltage to fully drain), and put everything back together. The noise in the signal seems to be from my scope grounding, so that is not audible in the speaker at all...
THANK YOU very much again!!!