essencedesign

iTrader: (1)

Hi , I wanted to first off say thanks for all the help I've gotten so far from these forums

I've just finished stage one of my install in to my Audi TT. Sub is single CDT Eurosport 12" and an older Kicker ZR240 Amp running bridged in to 2ohms.
I have power and ground leads directly off the battery. All so installed a JVC Deck.

I have rather nice Monster Home Theater RCA's running sub out to my amp.

Heres the problem. There's quite a bit of alternator noise from the sub. As well, and more importantly, when I touch the heatsinks of the amp, it produces a rather strong 'hum' through the sub. It's really weird. If I take off my shoes, and touch the heatsinks , the 'hum' get's way louder.
If i touch the powdercoated sections of the amp the hum is still there, but not nearly as loud.

If i disconnect the RCA leads from the deck at the amp and then touch it there is no noise at all.

This seems like some kind of ground issue to me, but I've even tryed grounding the amp in three different places including the battery and it dosnet make a bit of difference.

Tryed a different set of RCA's (cheapo's) and same problem.

Any idea's ??

Thanks

DesolataX

iTrader: (1)

Make sure you clean the paint off of the ground points, just use some sand paper. Make sure your battery grounds arent frayed or the terminals dirty.

essencedesign

iTrader: (1)

all good there, new wiring throughout and battery connections seem all good.
I will try and find a new ground point closer to the AMP on the chasis and see if that helps

LOUDGUY

sounds like you may have screwed the amplifier down to metal without the plastic insulators....

or the removable module is messing up.....

essencedesign

iTrader: (1)

Never thought about the Module, it is just the bypass one that is in there right now , using the deck to control the EQ.
I am seeing a few module units on ebay right now maybe I'll pick one up , I love these amps the sound is so clean from them , and they look nice and simple which i like I find so many car audio components these days look so crazy

JohnVroom

is it just the sub thats singing the alternator song?

Haunz

iTrader: (3)

there could be problems with the gear... but either way its a nazty ground loop and fixing that should fix the problem...

make sure the RCAs arn't touching ground and you need to attach 'muting plugs' to the amp to rule it out as being at fault.... if thats all good try powering the deck from a 12v battery thats not hooked up to the car and see if the the noise goes away....

thats where I would start, so check it out and let us know the results.....

If you are a n00b a little reading on the 1st site that pops up when you google 'basic car audio' should also help learn some basic stuff.... (like muting plugs)

s14_240sx

Definatly sounds like a grounding problem. As a quick check to rule out other things, use a different set of rca's attatched to a mp3 player and see if the noise is still there. As the other poster said, is the actual amp screwed down or touching bare metal? Check the spot where you grounded, and try putting the amp on some cloth or carpet (not on metal) if it already isn't. good luck.

essencedesign

iTrader: (1)

Hi everyone, thanks for all the replys. I don't think it's the ground off of the amp itself, I had the noise before i screwed it down at all. I think it has something to do with the head unit in some way.

The Alt noise is only coming out of the sub.

I'll spend some time trouble shooting through out the week, it dosent effect the sound really , only when you touch the amp ( get a big pop at first , then a steady buzz)

Thanks again

SheHateMe

I don't really know to much, but have you made sure you aren't running your RCA's close to your power wire (or ground wire? Not sure if the ground matters though)? I've been told by a few installers locally you always wanna keep the power wire away from the RCA's.