car stereo - digital noise/buzzing.

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sdavisnz

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Topic # 160465 7-Jan-2015 18:41

Hi,

I recently installed a android tablet as my head unit going to a 4 channel amp via 3.5mm to rca.

also recently upgraded all 4 speakers to 4channel pioneer 6" speakers.

problem, when pausing a song i hear a buzzing for about 3.4 seconds then it stops. also when listening to audio i can hear it in the background.

turned volume on AMP to medium and volume on tablet to 70%-90%

how can i fix this?

Cheers,
steve.

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Stu

Hammered
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Reply # 1210088 7-Jan-2015 18:47

Try a Ground Loop Isolator. Jaycar make one with a 3.5mm plug and socket that works well for in car installations.

ETA: http://m.jaycar.co.nz/m_productView.asp?ID=AA3086

Sorry for the mobile link. On my phone. AA3086 is what you need.

Keep calm, and carry on posting.

sdavisnz

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Reply # 1210104 7-Jan-2015 18:50

Thanks,

its very frustrating so hope it helps, ill let you know how it goes

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NzBeagle

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Reply # 1210107 7-Jan-2015 18:51

Watching Topic with interest, that would frustrate me too so might be handy to know some time. Out of interest, what is the tablet source? And can the problem be easily replicated with another source, eg, cellphone?

Stu

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Reply # 1210108 7-Jan-2015 18:52

2 people support this post

Does the hum go away when you disconnect power from the tablet and run off internal battery?

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sdavisnz

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Reply # 1210109 7-Jan-2015 18:54

will try now,

amp is nakamichi ngtd4
tablet is samsung android tablet
power source is cig lighter to usb 2.4 amp

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richms

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Reply # 1210133 7-Jan-2015 19:53

Its a ground loop, when the audio hardware of the tablet is powered down it stops as there is then nothing driving the signal at the tablet end.

Take a ground from the 5v side of your USB power supply back to the ground on the amp so its not going thru the rest of the cars wiring.

Richard rich.ms

sdavisnz

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Reply # 1210135 7-Jan-2015 19:59

richms: Its a ground loop, when the audio hardware of the tablet is powered down it stops as there is then nothing driving the signal at the tablet end.

Take a ground from the 5v side of your USB power supply back to the ground on the amp so its not going thru the rest of the cars wiring.

can u recommend someone to do this for me?

im not comfortable touching power cables in the car. even when its turned off

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Stu

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Reply # 1210144 7-Jan-2015 20:23

While what Rich said should work, the Ground Loop Isolator would be cheaper than paying someone to mod the cable. $13.

I use it myself and it works well. Search for it on Geekzone and you'll find your situation has come up before. Very common issue. The Isolator is cheap, quick and easy. The Jaycar model mentioned is great for this application.

Keep calm, and carry on posting.