Tons of audio noise problem

**hutacars** · 09-21-2009, 05:32 PM

I just got my carputer up and running today, but I'm having major problems with my amp. I know it's not the amp's fault, as I tested it beforehand and it was running fine.

As a temporary solution, I've simply hooked up a cigarette lighter cable running from the back of the amp into the lighter, until I get some relays/other stuff I need to do a more permanent install.

I have a short (8") cable running directly from the audio output on my Mac Mini into the RCA inputs on the amp. When the carputer is on and the amp has power, there is just a wall of noise. If I play music, I can hear it playing, but only just. When the carputer if off but the amp is on, there is just a loud whine. I was going to hook up an MP3 player to the other input, but that likely wouldn't make a difference since it makes noise even with the carputer off.

Any ideas are appreciated. Thanks!

**thewizard** · 09-21-2009, 06:52 PM

I know that you said this wiring setup is temporary, but until you run your amp's power all the way back to the battery you are going to experience the noise issue. That is in all likelihood your biggest problem.

**hutacars** · 09-21-2009, 06:59 PM

I now have an even bigger problem. I tried booting the computer with the amp already on, and it was only exhibiting low levels of noise, until suddenly the noise ceased completely. I looked down and noticed that the red light to indicate the cigarette lighter cable was in use was off. I plugged in a GPS, and it worked fine, so I guess the lighter is working fine, but I blew out my amp somehow. Likely next weekend I'll pop it open and check it out. Hopefully it's something simple such as a fuse. Once I fix it, I won't hook it back up that way, and instead make a point of purchasing everything I need and hooking it up properly.

**PaulF** · 09-21-2009, 08:58 PM

Or you blew the fuse that is built into the cig lighter cable. Most have fuses built into the connector.

**hutacars** · 09-21-2009, 09:22 PM

That's not possible, considering I was able to plug in my external GPS and it powered on like it was supposed to when the car came on, and asked me if I wanted to standby when I shut the car off. It has to be something related to the amp.

**PaulF** · 09-21-2009, 09:26 PM

Does the GPS use a different cable than than the one you are using to hook up the amp?

**hutacars** · 09-21-2009, 09:37 PM

Oh, I understand, I thought you meant there was a fuse built into the cable behind the cigarette lighter itself. I did not check for a fuse in the cable leading to the amp, but I shall tomorrow.

**PaulF** · 09-21-2009, 09:40 PM

If the cable itself has a light on it, I guarantee it has a fuse in it since it is more than just a simple connector.

That fuse is rated at 10 amps... 120 watts. You're trying to power a computer and amp off that. No way that will hold up.

**hutacars** · 09-21-2009, 09:44 PM

I figured the light just might come on only when it has a load, but you have a point. It's not powering the computer as well (that's powered directly off the battery), but I suppose even the amp alone could have exceeded 10A. There's no labels anywhere to suggest what it's rated at.