not to knock you ( pretty cool idea) but how log did it take you to work this up — and what is really wrong with splicing into the cig lighter or accy harness from the key to turn on your amp — the amp turn on doesn’t take all that much power to turn on — you could have used a regular 20/30 amp bosch relay at about 2 bucks and 5 min of my time — what are you using you cig lighter for anyway — most newer cars do not even put in a lighter– if you use a laptop i would stay away from using the cig lighter to ac adapter — if you already ran 8 or 4 ga wire for you amplifer( subs or mids and his just get a distribution powerblock and run a dc to ac converter and then plug in your laptop to that
still i think you have a great idea

Posted at 12:09 pm on Nov 10th, 2008 by digitalmaddog

i was wondering the same thing. why not a relay?

Posted at 12:48 pm on Nov 10th, 2008 by djrussell

why not just put the remote line on a switch and mount it in a place where you can shut it off when you roll by the 50 to avoid noise pollution tickets?? time spent wiring = 7.4 minutes, mounting a switch = 3 minutes…

Posted at 1:56 pm on Nov 10th, 2008 by chr0n1c

Why not just tap into the factory amp turn on wire? (same as the power antenna wire) Badda-bing Badda-boom instant 12v Remote turn on feed that turns on and off with the radio itself!

Don’t get me wrong – this is a nifty way to do it – and a nice circuit for doing what it does, but I don’t see it as being any easier or cheaper or cleaner than a standard remote lead setup.

Posted at 2:50 pm on Nov 10th, 2008 by smilr

The problem is that there is no remote line! The car’s stereo is always on and just goes into sleep mode whenever it’s locked for a certain (variable) amount of time. There isn’t an ignition line or anything. The car has 4 states of “on”, but are only detected internally within the radio/odometer…

And about the switch… I got a lot of heat from my friends from making stuff “overcomplicated” but in the end, it works great! Also, it’s unobtrusive and doesn’t require me reaching under my seat each time I sit in the car :)

Posted at 2:54 pm on Nov 10th, 2008 by war6763

Yeah, I’m really thinking a relay is the way to go here. I have a hard time believing there wouldn’t be SOMETHING that would be able to handle the minimal load it takes to switch a relay. But I do give you props for ingenuity!

Posted at 3:34 pm on Nov 10th, 2008 by Smokin Lights

I guess I don’t understand the problem with using the cigarette lighter for the amp signal wire… the signal wire should just be going to the amp’s internal relay. My fiance has a mini cooper and that’s how we wired it up. Amp power goes directly to the battery with an in line fuse but the signal wire attaches to the cigarette lighter.

Posted at 8:40 pm on Nov 10th, 2008 by twistedsymphony

not to rain on the party, but this “hack” violates the kiss principle (keep it simple stupid) in just about every way. if engineers spent their time trying to find the most complicated ways to do things, nothing would ever get done. it may work just fine, but that doesn’t mean it’s a good idea.

Posted at 2:24 pm on Nov 11th, 2008 by andrew

Why don’t you look at connecting it to the audio output of the head unit, that way the amp activates based on a level output greater than a certain amount. I’m sure in “sleep” mode the audio outputs are zero, but when on, even muted, the audio outputs generate some noise (DAC deadband) that can be detected (a few millivolts).

Posted at 10:13 pm on Nov 11th, 2008 by Perry