Ground isolation method

[badboy6120]

Hi everyone

I was working on my class D car amplifier and finally I finished it today but when I install the amp in my car as soon as I connect the car stereo ground to the amplifier input, there is a magor current drawing from battery

I use this DC to DC convertor for my amplifier:
800W DC-DC Power Supply

and this is the class D amplifier that I used:

900W Class-D Next Generation Power Amplifier - Class D Amplifier Circuit

If I connect my amplifier input to another external audio device like Mp3 player, there would be no problem and everything is okey

How could I isolate my amplifier from car stereo?(grounding problem)
every helf would be appriciated🙂

 

[ekbrus]

Ground loop isolator,easy way if low frequencies are not important

 

[badboy6120]

How much low frequency do you mean?
as this amp is Subwoofer amplifier

 

[badboy6120]

How this is done in commercial amplifier as they connect to car stereo without any problem
am I missing some circuit board here?

 

[ekbrus]

when using an ground insulator the drop is below 50 Hz at best.
if you have a subwoofer load, then no way out.
try the preamp and check the ground circuit.

 

[badboy6120]

Does anyone know how they deal with this problem in commercial amplifiers?
I don't see any ground loop liolator circuit in every amplifier board on the web
So can this be done with preamplifer or something else?