Switched from a/b to D -- now engine noise.

[n2audio]

Was running a Lanzar Opti100.4 (Zed) bridged to run my components. I replaced it with a Lanzar Opti4x400d (Korean).
This was a direct swap. I just disconnected the 100.4 and connected the 4x400d.

The Zed was essentially dead quiet, and the 4x400 has obvious engine noise. At low-mid volume it can't be ignored. At high volume it's not noticable.

Is there a how to somewhere for troubleshooting engine noise?

Does anyone know of an issue with these amps as it relates to engine noise?

 

[luka]

check you ground, make sure it is really good
same setup, same position(cables and all), diffrent amp only amd it does this?

 

[n2audio]

The only thing that might have changed slightly is the position of the last couple feet of the cables from where they enter the trunk and connect to the amps.
Other than that, yes, everything is the same.

 

[luka]

signal cables still away from power cables? maybe you would need to unplug everything and redo it again in case that helps, i not, maybe try old amp again

I'm not sure amp is the problem, but you never know

 

[odnaizutra]

maybe your problem has to do with the way the amplifier is grounded internally.If you have some electronics knoledge,try to discover the difference between the old and the new one at the pre amp grounding.maybe you have a loop ground at the the pre amplifier and the chassis of the car.Tryto put an audio isolation transformer between rca inputs and rca cable and verify if the noise stops.If so,try to modify (or ask a technician),or even contact the factory to see if they can help.