Remote power connection.

[jnb 10+ year member]

Hi,

I had my amp connected for testing with the power cable running into the power and remote terminals. The power cable was running beside the RCAs (yes, I know) but it was quiet.

I then connected the remote to my head unit's antenna/amp lead as it should, but now there is noise. What is likely to be the cause? will I need filters, and where?

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[Chevillac 5,000+ posts]

What kind of head unit and amp?

 

[Death By Bass 10+ year member]

I assume that the remote wire from the headunit is running with the RCA's...

that would be the problem I'd say...

 

[jnb 10+ year member]

Sony H/U, kicker zx460.

I assume that the remote wire from the headunit is running with the RCA's...

Side by side, you mean? Yes they are. I assume you mean that the noise is getting induced into the signal leads from the remote lead.

OK, I can move it, but:

1. Doesn't that mean the H/Us power is dirty?

2. Doesn't the amp's remote terminal only need to sense the 12V for switch on, end of story? or does the noisy 12V at that terminal affect it?

 

[mlstrass 5,000+ posts]

Some RCA cables come with the remote wired built in, so my guess is check your HU ground since you're now adding that into the mix.

 

[Death By Bass 10+ year member]

Some RCA cables come with the remote wired built in, so my guess is check your HU ground since you're now adding that into the mix.

its not a remote wire.

and, its quite possible that the motors in the CD player, are inducing noise into the remote line //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[jnb 10+ year member]

That could be so. AFAIK, my biggest problem is alternator noise.

 

[jnb 10+ year member]

Tried repositioning the remote wire but it doesn't help.

 

[jnb 10+ year member]

I put a simple filter onto the remote wire at the amp. I also screwed some heavy ground cable straight onto the floor pan for the headunit and disconnected the old ground, but no difference.

 

[Death By Bass 10+ year member]

ground loop through RCA cables...

try unplugging the RCAs at the amp, so just the middle pin is making contact, and not the ground connection on the outside.

 

[jnb 10+ year member]

****ing champion!

I need to make up some RCAs of the right length so I'll just connect the shield at the HU end only.

 

[Death By Bass 10+ year member]

****ing champion!
I need to make up some RCAs of the right length so I'll just connect the shield at the HU end only.

yup, now, wheres my money?

 

[jnb 10+ year member]

Here's $100 //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Seriously though, thanks for the help. I think I'll hang around and see if I can maybe help some others with what I know.

 

[helotaxi 5,000+ posts]

I assume that the remote wire from the headunit is running with the RCA's...
that would be the problem I'd say...

*cough*BULLSHIT*cough*

There has to be a serious flow of alternating CURRENT to induce noise. The current in your remote wire is only a couple hundred milliamps at most and is not alternating.

its not a remote wire.

Actually in a lot of cases it is...

try unplugging the RCAs at the amp, so just the middle pin is making contact, and not the ground connection on the outside

Depending on the topology of the HU and amp, the outer part of the RCA is simply the other half of the signal, not a ground. The signal is ground isolated to keep from introducing noise into the signal from ground loops. By partially disconnecting the RCA all you did was cut the circuit so no signal is passing. If you are going to try to cut the shield, you need to ground it.
It really sounds like you have a grounding issue with the HU. Either the signal is not ground isolated (which sucks as a design) or the HU is damaged resulting in the signal not being ground isolated (a common problem with Pioneer HUs, though I wouldn't rule that out just because you have a Sony).

 

[Death By Bass 10+ year member]

Depending on the topology of the HU and amp, the outer part of the RCA is simply the other half of the signal, not a ground. The signal is ground isolated to keep from introducing noise into the signal from ground loops. By partially disconnecting the RCA all you did was cut the circuit so no signal is passing. If you are going to try to cut the shield, you need to ground it.

It really sounds like you have a grounding issue with the HU. Either the signal is not ground isolated (which sucks as a design) or the HU is damaged resulting in the signal not being ground isolated (a common problem with Pioneer HUs, though I wouldn't rule that out just because you have a Sony).

ah... we already solved the problem thanks dumbass //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif