I have a little Sony 222 amp which is overloading.

It is under my passenger seat. It's inputs are line level (4V) via RCA cables from the head units RCA out.

Recently on a very hot day I was sitting in a car park with the engine running waiting for my significant other. I was mucking around with the stereo and turning it up reasonably loud.

15 minutes later we were driving and the sound dropped out. I turned it off, waited, then turned it on again. It worked for a short period then dropped out again.

That was a few weeks ago and it's done this a few times since. Today it happened again. If I wait a little while then play it at very low volume it's alright. Bump up the volume and it drops out again.

Anyone have any ideas on this? Is the amp totally stuffed?

 

AUSS2000,

During these times of audio cut out, does the amp feel physically hot? Most quality amps have temp sensors that retard output when too hot. If the amp is really hot to the touch, your problem could be its inability to cool enough under the seat. Analog amps aren't the most efficient devices and put out a ton of heat...

If my diagnosis was correct, either fabricate a fan/cooling system (which turns the fan on with the 12v remote lead) or purchase an amp with built-in fan.

Are you also using sufficient guage wire for the amperage requirements of the amp? One of my first installs about a decade ago, I ran ~22 guage power/ground to a 200watt amp and it kept overheating/shutting off (I was starving it for power) and when I gave it suffiecient guage wire, it worked beautifly...

Just a few ideas from years of making stereo messes and learning from my mistakes!

 

It did feel quite hot the first time it happened, but since then it shuts down and it's stone cold. I've tested for this several times.

I'll redo the wiring as currently (no pun intended) it draws it's power off the head units miniscule power wire. I'll run some direct cable from the battery and see how we go.

Much appreciated. From the pictures of your install it's fairly obvious you've been through this in depth.

 

Bingo! And the meat tray goes to shaner!

When I did the amp install I just tapped into the power to the head unit, which as you know, uses amazingly thin wire.



Tonight I ran a line direct from the battery to the amp and it worked great. Tomorrow I'll put a fuse in and run the line through the firewall.

Once again, thanks to you shaner for your help.

 

Pinky shakes his head wondering how the fuse for the radio never blew!

 

Aus,

The general installer rule when running a power cable directly to the battery is to make sure that there is a fuse within 6" of the connection to the battery. This is not a fuse to protect the amp but rather a fuse to protect the battery: If you ever get a short from the (+) battery terminal to the frame (for example... maybe the insulation melted, got cut from a sharp piece of steel, etc) the wire will heat up (in the process burning off all insulation) until the wire melts, the battery bursts, or the battery runs out of current...

I know this from experience ~10 years ago when I didn't fuse my battery runs... now, always a fuse as close as I can!

Please, learn from my mistakes

 

Already covered that one. Presently there is an in-line 20 amp fuse about 4 inches from the battery terminal.

I'm having a bracket made to mount a fuse box in the space next to the bettery and will run some heavy cable to it then the four leads from each fuse through the firewall.

 

Running one big 4 aug wire into the car then using a splitter would be a better way of doing things. This way you got upside room to grow and only 1 hole in the car and you can seal it from leaking.

Just a thought.

 

I thought of that, but I can't find a decent point to mount the fuse box in the passenger side of the car that is still accessible.

 

Sure you can! Right behind the seat. On the floor in the middle. You just gotta slide the seat up and prop it forward and vulaha there it is.