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Discussion Starter · #1 ·
First time I've had something like this happen in forever . Cheap amp only unit and speakers , sounds great UNTIL you turn the ignition on and then you pick up every electrical noise from starter motor cranking over, alternator whining to even indicators clicking :(

If I turn the amp on , and then just turn the ignition on without anything else I get a drawn out whoop sound...WTF ?

It had a unit in before, mounted in a different place and that worked fine Is it a poor shielded amp unit or something else ?
 

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Discussion Starter · #5 ·
you are picking up interference off your remote cable usually the blue wire from the head unit, run a separate ignition live to the amp
All I have is the amp so everything else is just plug in ie personal cd /mp3 / cassette. Power in via jack lead with live straight from battery constant live. Speaker feeds out , that's it.
 

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Discussion Starter · #6 ·
how good is the earth connection
It 'should' be good ,bolts to the same brackets that also hold and earth the amp itself . However thinking about it the bolts pass through a plastic fascia so I'll try another another to a different source to rule that out. Only one earth on the system.
 

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There is a simple reason Kev, and it is cost.
Like most things these things are built down to a price rather than up to a quality. That means the manufacturers ut parts to save a few pennies, but a few pennies x 100,000 units adds up.
I would lay money on the filtering on the supply lines is none existant, so you need to make up a filter to smooth out spikes, whistles and farts on the DC input.
Quite simple to do, you need to find a ferrite rod, the sort that was the aireal in old fashioned wireless sets, the sort that recieved Jimmy Young.

Where your supply cable plugs in to the jack, unplug it. Wrap it spirally along the length of a ferrite rod, allowing enough to connect at unit. Wrap it with electrical tape, and that should cure your interferance problems.
 

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Discussion Starter · #13 ·
There is a simple reason Kev, and it is cost.
Like most things these things are built down to a price rather than up to a quality. That means the manufacturers ut parts to save a few pennies, but a few pennies x 100,000 units adds up.
I would lay money on the filtering on the supply lines is none existant, so you need to make up a filter to smooth out spikes, whistles and farts on the DC input.
Quite simple to do, you need to find a ferrite rod, the sort that was the aireal in old fashioned wireless sets, the sort that recieved Jimmy Young.

Where your supply cable plugs in to the jack, unplug it. Wrap it spirally along the length of a ferrite rod, allowing enough to connect at unit. Wrap it with electrical tape, and that should cure your interferance problems.
I pretty much guessed that Andy , it doesn't give the impression of being 'top end' ! LOL Several friends have used these before and it was the petite size that appealed along with being able to hide it from view.

I have already bought an inline filter but wanted to try to fix it properly first.
 
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