Simple & cheap way to hook mp3 player to stereo

(melvinator) · (melvinator) **Join Date: Apr 2001** 07-31-2005, 3:05 PM

I want to play my mp3 player in the boat but have an older stereo. I got to thinking and this is what I came up with and it works great! No rf mod thing to deal with either. All I did was splice on old pair of ear buds to a set of old rca jacks and plug it into the amp. I am going to buy a set of y-splices tomorrow so I don't have to unplug my amp every time. I can't be the first guy to think of this am I?

(wakeprodigy) · (wakeprodigy) **Join Date: Oct 2002** 07-31-2005, 3:18 PM

I bet that you are going to get some high quality sound with that contraption... just kidding. You will probably have to adjust the gain on your amplifier to match the output of your mp3 player, which would be a pain in the butt. Have you checked the output voltage of the mp3 player? I'm sure that is probably quite a bit lower than your head unit. Because of this you will have to increase the amplifier's gain to match your mp3 player's output level (in order to minimize signal reflections and maximize power output). If you have to increase the gain too much this could lead to your amp overheating.

(melvinator) · (melvinator) **Join Date: Apr 2001** 07-31-2005, 3:31 PM

That set up was to see if it would work, I will get better cables and solder and tape everything. The gain is pretty high on my amp right now, it sounded good when I cranked it up. I will do it right tomorrow and let you know how it works out.

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 07-31-2005, 3:42 PM

You could just buy a radio shack 1/8" stereo plug to twin RCA's, that's what the rest of us do.

(melvinator) · (melvinator) **Join Date: Apr 2001** 07-31-2005, 4:00 PM

Thanks Psyclone!!!! I did not know they make those. That will save me some time tomorrow :-)

Do you have much trouble with gain and working correctly?

(cyclonecj) · (cyclonecj) **Join Date: Jul 2001** 07-31-2005, 6:36 PM

I use an Ipod Shuffle, I just turn the volume up on it until it is about as loud as the CD. It takes more current to drive a pair of headphones ( relatively low impedance, 50 ohms) than it does to drive a high impedance stereo input, 50K ohms.

I've got mine hooked to an aux in on my Alpine head unit, so I control the gain from there. It shouldn't make a hell of a lot of difference, line level is line level. That means anything from .1vac to around 8vac for high end head units. Your MP3 player probably puts out .2 VAC (200MV) or so. I haven't checked mine with an o'scope yet but I may if I get bored. It's damn loud, and the battery lasts 7 hours.

I would probably buy one of those small RCA input switchboxes and put it before the amp, so you won't have to crawl around plugging in cables, you can just switch between the head unit and your MP3 player. I wouldn't worry about overheating your amp by driving it with an MP3 player, the worst thing that would happen is that you would have to turn the gain on the amp so high that the music get too noisy. The funny thing is, most peoples ears are so bad that they can't hear noise until it gets to about 10% thd.

You can also buy a small line level preamp that would boost the MP3 player signal to a level equal to that of your head unit. They are about 20$ I think.

(melvinator) · (melvinator) **Join Date: Apr 2001** 07-31-2005, 6:57 PM

Thanks for the info. I am just going to buy some kind of y-splice for input and just turn off the deck when I want to use the mp3 player. My mp3 player was only $40 from ebay and holds like 50 songs, that should get me through the week. I always forget cd's and when I bring them everyone borrows them or they get scratched. I have friends with ipods, now they can bring them instead of cds.

(talltigeguy) · (talltigeguy) **Join Date: Sep 2003** 07-31-2005, 7:37 PM

Remember Melvin that most people have their amps hooked up so that they turn on when the stereo is on. If you turn your deck off to listen to the MP3, you may have to wire the amp remote wire directly to the battery, I'm not sure that's wise.