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[Phil B]

I'm fitting an aftermarket amp to the underside of the parcel shelf. I remember reading in the installation instructions of an old amp ages ago that you had to isolate the chassis of the amp from the 0v chassis of the car. Is this a general thing for all aftermarket amps?

Cheers
Phil

[Dave DND]

I'm fitting an aftermarket amp to the underside of the parcel shelf. I remember reading in the installation instructions of an old amp ages ago that you had to isolate the chassis of the amp from the 0v chassis of the car. Is this a general thing for all aftermarket amps?

Cheers
Phil

Wow, that was a LONG time ago - when extra amps gave out nearly 10 watts per channel - any amp that required that kind of installation procedure would have been killed off long ago, and the rules from back in the eighties can now be firmly ignored and forgotten.

Modern amps must indeed be earthed

It is important that you run a suitably heavy earth cable that is as short as practically possible to a good earth point on the chassis of the car. If the amp is going under the shelf, then I would suggest a nice big fat self tapper drilled through some nice shiny metal on the boot floor close to the base of the suspension turret.

Do not be tempted to use existing bolts or seat belt anchorages as this may lead to another problem of interference due to earth differential.

 

[Phil B]

Cheers Dave

I'm alright getting a good 0v connection from the car body to the negative amp terminal, I just wanted to confirm that it's alright for the amp's extruded body to touch the car chassis.

I think it was a 120W Pro sound amp that came with these plastic insulators to prevent this, and warnings of death otherwise!

[Marks DTM Calib]

You want it bolted well to a metal surface as the install position you are opting for will give little air cooling over the heatsink based extruded case....so you need to rely on cunduction cooling to the body work.