One amp powering another?
 

I installed my amps and subs today. I ran the RCA cables from the head unit to the first 150 watt amp and then another set of RCA's from that amp to the 1500 watt amp. One thing I have noticed is that when the truck is off, the 150 watt still has the power light on. I disconnected the power and ground but the light stayed on. If I remove the RCA cables connecting the 2 amps, then it will go off. The 1500 watt amp has an internal capacitor. I was wondering if possibly the stored power is powering the 150 watt amp through the RCA cables. I'm kind of afraid to leave them connected as I dont want it to drain my batteries. Both amps have there own power supply as well.

You have the remote wire hooked up?

Yes.

Does your head unit only have one set of RCA outputs?

Yes.

Regarding the remote turn on wire, it's run to both amps.

Not sure on that one, I will have to ask around.

Couple of questions:
Why run two amps in that fashion?
What is the 150W amp powering?
Do you have one set of wires (power, ground, remote) for each amp?

Most amps don't have output RCA jacks, normally just input. The output would be for the speaker wire. Are you sure your amp has output RCA jacks?

Sorry for all the questions, just trying to figure this out to help you.

:U:

You could try running a set of RCA (Y) adapters off from your main RCA cord then to eack set of inputs on the amps instead of using the output on one of the amps. You can get them at Radio Shack for pretty cheep. Also is the radio wired to stay on when the ignition key is turned off. If so it might be leaving the remote turn on wire hot. I have seen some older radios do that even with the radio shut off. Amps stayed on with the radio shut off untill the power was turned off going to the headunit.

I'll look into the Y-adapters. The head unit is powered the same way the stock radio was. I used a Metra plug adapter that hooks to the factory plug on one side and an aftermarket radio on the other. I tried disconnecting the remote wire as well, but the light still stays on. Unplugging the RCA's is the only thing that will turn it off, it's pretty weird.:humm:

:humm::humm::humm:Let me think on this. I have two friends that own 2 diff car audio shops. I will give them a call and see what they say. Might be Monday before I get back to ya.

I think something is wrong somewhere. If you've disconnected the power, ground, and remote and the light is still on there is something wierd going on. Have you tried reversing the RCA's (put them in the large amp first then come out of that amp to the smaller)?

Dude, thats crazy hope ya get worked out.

When I got home home today, I shut the truck off and decided to watch the light. Oddly enough it shut off after about 15-20 seconds. I guess thats good, it still seems weird that it stayed on before. I had time to loosen the screws and remove all 3 wires individually and then all together and it never went off. Oh well, who doesn't love a problem that solves itself. :ok1:

don't put a Y in the rca pugs o the radio. you'll lose your sound quality. the reason there's 2 plugs is for each side may have it's own personal sound. you could do it if you wanted mono sound though and not stereo.

Yes you can. Just don't run one side of the RCA cord to one amp and the other to the second amp (that would make it mono). You would run the Y's to split the right half to make 2 right sides and then split the left half to make 2 left sides. Now run 1 rt/lt combo to one of the amps and the other rt/lt combo to the other amp. Yes you are still going to have stereo. Back in the day when head units only had one set of RCA outputs this was the only way we could run multi amp systems with out running a EQ or a Thirdoctive Eq. Or we would have to run a speaker to RCA convereter off from the speaker leads.

this would be a very good question to ask on this forum-- Car Audio Classifieds - Buy, Sell and Trade Car Audio Equipment. im going to copy paste your question to a thread on the site and see what i get. you should go check it out as well. great audio forum

It's not unusual to have a head unit with one or even two RCA pre-amp outputs. Unless your amp has a pre in & out then the the best thing to do is what was suggested earlier, a pair of RCA Y-cords that allows you to input both amps with the same signal. Jumper the remote turn on wire (or power antenna) to both amps to turn them on via the head unit.

You guys do realize that the RCA output on an Amp is just a passthru right?

The microfarad capacitance of the capicitor will determine how long the light will stay on.

:humm: if the amp has inputs and outputs, i would think you would use the outputs for multiple amps (as in very high wattage systems) - that's why they put them on the amps... My assumption is that they have a small voltage boost on each output to allow for low or no signal loss as you split them from amp to amp... if you ran a bunch of "Y" connectors, it seems you would constantly lose signal voltage and gain noise to volume ratio... This is obviously just a bunch of assumptions i'm throwing out there...

As far as your light staying on, you got me on that one... unless it's a cooldown period or a power drain period... if it has something to do with your RCA's then I assume you have some internal problem that is not intentional to the amp(s) manufactuer...

again... JMO :tu: