Modding a radio

[jakeao]

I recently hacked into the radio at work to put in an Aux. jack to plug in an mp3 player. Everything works, but I have to turn the volume way down on the mp3 player and then crank the radio for it to not distort. I understand that the output of the mp3 player is hotter than the output of the radio where I spliced into it. Here is what I don't understand.

I turn my mp3 player down to "1" then turn the radio all the way up. It sounds clear, but not very loud. I turn my mp3 player to "2" and now everything is distorting, but still not very loud.

I can switch it over to the radio and it get s really loud. Way louder, than the mp3 player and it isn't distorted. I tried putting some resistors in line with the mp3 player, to knock the signal down, but it just does the same thing as turning the mp3 player way down. I lose a lot of volume. What am I missing that I can't get the radio, and mp3 player signals to be the some volume, and not distort. Let me know if this doesn't make any sense. Thanks for any help.

[CurtZHP]

Is there a different point in the circuit where you could patch in the player?

Or just get your cheapskate boss to spring for a better radio with an aux input built in!

[strdsk]

Jakeao...I love your quote man...lol! They filmed that movie right near my house!

[jakeao]

Glad you liked the quote. As far as patching into a different spot, the place i patched into is really the best. there are three wires taht come from a plag that says "to main volume" There is a ground a common, and one signal wire the radio is mono.

[The Scum]

the place i patched into is really the best.

If it's really, truly is the best, then what's with the distortion?

You need to figure out what stage is distorting, and address that. It could be that the MP3 player outout is just too hot, and the radio is crapping out. It could be that the node in the radio you've hacked is a virtual earch, and the MP3 player output is distorting, because it's trying to drive a ground. It could be something else completely...

Once you have an idea of what the bottleneck is, we can come up with a specific fix for the problem.

[jakeao]

If it's really, truly is the best, then what's with the distortion

Oh SNAP!!!

Anyway, I guess by best I meant easiest. The electronics for the cassette player are on one board, and that board has the wires going to the other board with the tuner, and main volume controls. The output on my Zune is around 300 mV when cranked, and around 90 mV when at the lowest setting. The output from the cassette portion of the radio is around 90mV.