Amplifier whine?!?! Please help!

[knightrider3580]

Hey guys,

Question for yall.

I got an amp from someone on CL a week ago part of a package deal. I got the amp hooked up and it powers on but a i get a constant whine out of it. I took it out and put it in my bench and directly hooked it up to a battery and a speaker w/o an input signal and i get the same whine. Keep in mind it whines w/o any input signal. Also i cleaned the board with circuit board cleaner and it still does it, also it doesnt go into protection. I did notice the whine goes in and out with the bass remote being adjusted. Also if the bass remote is disconnected the whine is a constant pitch. I cleaned and adjusted all the pot knob settings hopeing they were dirty but didnt help. Also the amp is a class d mono block w two out puts and both outputs have the same whine. If its any help its a maxxsonics hifonics brutus 1200W class d monoblock.

Btw the amp is for off road 4RUNNER not my dd which u all know has PG!

Please guys any help or suggestions would help.

[trickyricky]

May be the filter caps on the outputs are bad. They are big rectangular shaped....right by the speaker terminals. That would be a guess, is it a high pitch whine or low hum?

[knightrider358]

Its a high pitch whine coming from it

[knightrider358]

What would have caused it to do this

[trickyricky]

Am not certain that the fault or cause is the filter caps on the outputs...more like a guess. It could be something else causing it in the signal section. Perhaps before or after the op amps, you would need an oscilloscope to find where the noise is being emitted. I don't like messing with class D amps or the G/H, so I can't tell you exactly what the problem may be. Guys at Diyaudio.com (Perry or Cecil) may be able to help further more.