Alternative question - how do i line my mp3 player into my stereo?

[repenttokyo]

I cancelled my XM service today and I have been using my Zune with its FM transmitter as entertainment in my car. The trouble is, the FM transmitter is absolute garbage.

Second problem: tape player in my car is no good, so I can't use a tape adapter.

Is there any way I can hardwire an AUX input into my receiver? I really don't want to have to replace the head unit - I like the all stock look.

[Tiger]

I think you can use the CD changer wire to send sound in... Basically you need to figure out which two wires act like left and right channels line in. I think someone did this long ago. maybe you can search it on this forum.

[repenttokyo]

I'm looking at something like this as a possible option:

http://www.crutchfield.com/p_142FMMOD01/Scosche-FM-MOD01-Modulator.html?tp=1701

I've taken apart my Zune transmitter to see if I could add an extra length of wire to the internal antenna, but so far no luck as it's much more compact than the original.

[attack eagle]

those work, won't be as nice as a direct line in on the changer input.

[Rick L]

This works if you have BMW Alpine C33 or C43. I found this from another BMW forum and it's a great idea to add line-in into TAPE line. :) See below...


So you have a nice iPod / iPhone but you cannot connect it to your factory stereo system because it has no aux input.

I have the Harman Kardon system installed in my car with the 10 speakers and a CD changer in the back. I wanted to keep the CD changer so that ruled out most of the adapter boxes that replace the CD changer with a connection for an iPod/iPhone.

Here's what I have done. First, I read the following thread: http://www.r3vlimited.com/board/showthread.php?t=118781

The guy did a good job. I thought about the same idea but actually didn't know how simple it is going to be.

You will need:

- A BMW radio key (you can use a 2mm Alan key instead).
- Your radio CODE! Very important. Do not take the radio out without having the code.
- a 3.5mm stereo plug with a cable. A few $ at Radio Shack. I just used an old one I had lying around.
- A VOM (voltmeter) to check continuity.
- A soldering iron with a small tip and some solder.
- A cutter to cut the wire.
- Some tape.

First, you remove the radio from your car using the radio key. Then unplug the plugs at the back. The main plug is a bit tricky but follow the illustration on the top of it and it will come out.

Next, Remove the 2 screws holding the top cover. If you look at the back of the radio they will be the top left and top right ones. They pry the top cover off with a flathead screwdriver.

Inside the radio you will see the tape mechanism. It is held in place by 4 screws. Remove them and pull the tape mechanism out. It is sitting on the main board with a plug much like the one in the back of a hard drive but with only one row of pins.

On the back of the tape mechanism there is a PCB with electronic on it. At the top left of it there are connectors coming from the tape reading head. Look at the picture below.

http://www.tomerlitvin.com/photography/albums/BMWradio/Resize_of_2008_11220018.JPG

Before you solder anything pass one side of the cable through the top cover like in the picture below. This is after the radio was already assembled together but you get the idea. Pass it towards the rear of the cover. Leave enough cable (I left about 2.5 feet) so it can reach around to your iPod.

Take your stereo cable and solder the end of it to the board as in the picture above. The left most soldering point is GROUND. The second one is RIGHT CHANNEL and the 3rd is LEFT CHANNEL. Referenced from here: http://en.wikipedia.org/wiki/TRS_connector

Test to see that everything is connected correctly and that you did not create any shorts.

Tape the cable to the back of the tape mechanism so it does not get pulled and take the soldering points with it.

Now, a little trick. If you look at the picture below you will see a small, black micro switch in the center of it. It has 4 legs and it tells the radio that you have inserted a tape in it. When you put the tape in a mechanism of levers will release this switch and will operate the tape loading arms. We need to disable the switch and we do this by removing the spring and then pushing the arm that is holding the spring down.

http://www.tomerlitvin.com/photography/albums/BMWradio/Resize_of_2008_11220017.JPG

Tape the spring and the arm to the top of the tape mechanism so they don't move. I left the spring in there in case I ever want to put it back together.

Tape used mode, see picture below...

http://www.tomerlitvin.com/photography/albums/BMWradio/Resize_of_2008_11220021.JPG

Put everything back together. Put the tape mechanism back in it's place and the screws that hold it. Route the cable inside the radio so it is not disturbing the top cover.

Back to the car.

Put your finger through the hole in the top of the sunglasses tray and push the climate control unit out. You DO-NOT need to disconnect it.

Route the cable like in the picture. In through the right back side area of the radio location and down through the hole in the sunglasses tray.

Install the radio back. First plug the cables. Turn the key on and turn the radio on. It will ask for the code (I hope you have it) and then you will hear the tape mechanism work loading the nonexistent tape. This is because we have set the micro switch to TAPE IN position. It will only happen once.

Connect an ipod and press the TAPE/CD button. It will show TAPE A and you will hear your iPod. Press the button again and it will operate your CD changer.

Push the radio back in and use the radio key to turn the screws. Put the climate control unit back in.

If you want to have the option to charge the iPod as well you can buy this: http://www.griffintechnology.com/products/autopilot

You plug your AUX input to the AutoPilot and the iPod to the AutoPilot iPod connector. This way you only have one plug to connect your iPod to when you put it in your car and it will charge it and play the music.

Picture of final installation. The iPhone cradle is also made by Griffin.

http://www.tomerlitvin.com/photography/albums/BMWradio/Re-

[Rick L]

Final picture with TAPE selection to access tape line-in for iPod or other MP3 players. And you get to keep CD changer. :) But maybe you can do similar with orther radio with tape player or even put toggle switch for line-in from CD changer as well...

http://www.iccrents.com/ICC/Driver/Tape.jpg

[repenttokyo]

That's a great tutorial. Unfortunately, I don't have a CD player in my trunk, so I am not sure that any of that applies to me.

[uscharalph]

If you have a C43 you can use a DICE unit. CD43 is better. iPod is better also.

[repenttokyo]

How do I know what model radio I have?

[tim eh?]

That's a great tutorial. Unfortunately, I don't have a CD player in my trunk, so I am not sure that any of that applies to me.

that is the #1 way to go dude - you would be stealing the deck's hardwired 'tape in' and turning into an external aux in.... then you can run anything to it. the only trick is finding the L/R/ground on the circuit board in the radio. i'm sure a radio/tv repair guy would do it for cheap if you don't want to. nice writeup rick!

don't get those FM transmitters they are super lame, you lose sound quality in the FM conversion/reversion.

an aftermarket stereo is pretty easy, even if you can't find an appropriate connector/adapter on ebay the wiring is pretty self-evident. on the head unit you only have hotalways/hotwithignitionon/ground plus the speakers (8 wires) plus a remote power send for the factory amp also. the bummer is unless you do the amp bypass you aren't getting the most out of your new head unit, but it still works alright. the grounds aren't a worry... there is a place to ground them on the amp input... common advice seems to be to tie them together but i still disagree with that. i still would suggest option #1 as fastest, easiest, and cheapest.

[repenttokyo]

that is the #1 way to go dude - you would be stealing the deck's hardwired 'tape in' and turning into an external aux in.... then you can run anything to it. the only trick is finding the L/R/ground on the circuit board in the radio. i'm sure a radio/tv repair guy would do it for cheap if you don't want to. nice writeup rick!

don't get those FM transmitters they are super lame, you lose sound quality in the FM conversion/reversion.

an aftermarket stereo is pretty easy, even if you can't find an appropriate connector/adapter on ebay the wiring is pretty self-evident. on the head unit you only have hotalways/hotwithignitionon/ground plus the speakers (8 wires) plus a remote power send for the factory amp also. the bummer is unless you do the amp bypass you aren't getting the most out of your new head unit, but it still works alright. the grounds aren't a worry... there is a place to ground them on the amp input... common advice seems to be to tie them together but i still disagree with that. i still would suggest option #1 as fastest, easiest, and cheapest.

EDIT: I understand the above tutorial now. I thought that he was connecting to the CD player controller in, now I see it is the tape itself. I feel like an idiot. Thanks again for all your help guys, I am going to try this later in the week when I have some free time.

It's not too difficult to get the tape deck out, is it? I assume the procedure is in my Bentley.

[tim eh?]

since my car isn't equipped with the CD changer, is it still 'ready' to have one installed? I am just concerned that I will yank the stereo out and not see the necessary solder points.

if you had a cd changer it would have its own channels seperate from the tape's.
your stereo head would switch between these when you pressed the 'mode' or equivalent button on the stereo.

there might even be an unused circuit for your nonexixtant cd changer.

my aux in is hardwired into the cd channels, but i could have done it through the tape channels.

btw you will get way better sound quality if you go the whole 9 yards and put in an aftermarket head. i think the speakers are really good in these cars but the factory amp kind of bites. but to do it properly you have to bypass the amp... which isn't a big deal really... myself i just haven't gotten around to it yet, too many other things keep breaking and rusting on me!

****- just thought of this.... you could bypass the head and send the mp3 player straight into the factory amp, but you would lose the radio.

[Tiger]

Very easy to take out... just flip the two side door open... use close enough size allen key to loosen and then slide it out. Wiring harness is easy... slide it up and it will release the plug.

Remember, you do need the code when you plug it in again. Opening up that chassis to get to the tape deck is super easy.

[repenttokyo]

Very easy to take out... just flip the two side door open... use close enough size allen key to loosen and then slide it out. Wiring harness is easy... slide it up and it will release the plug.

Remember, you do need the code when you plug it in again. Opening up that chassis to get to the tape deck is super easy.

let's hope my tape deck at all resembles the photos in this thread.

[tim eh?]

let's hope my tape deck at all resembles the photos in this thread.

if not it will probably be printed on the circuit board itself ch1/ch2/gr all next to eachother or something like that. maybe 'ca' or 'cs' for 'tape'

or at worst you have to trace the circuits back from the line out wires at the back of the head unit.

[repenttokyo]

Ok, so here is an update.

Pulled the stereo apart today. The PCB doesn't look anything like what is pictured for the newer radio.

Here is a picture of mine. I have circled what i THINK might be the leads - bc these are the only connectors which have wires leading off of them. Nothing is labeled.

Anyone have any ideas? I don't want to risk an inoperable stereo.

[tim eh?]

Ok, so here is an update.

Pulled the stereo apart today. The PCB doesn't look anything like what is pictured for the newer radio.

Here is a picture of mine. I have circled what i THINK might be the leads - bc these are the only connectors which have wires leading off of them. Nothing is labeled.

Anyone have any ideas? I don't want to risk an inoperable stereo.

that looks like the back side of the board... info would be printed on the other side, unless that's some japanese there - looks like it's only one screw can you take it off and look at the other side?

[repenttokyo]

that looks like the back side of the board... info would be printed on the other side, unless that's some japanese there - looks like it's only one screw can you take it off and look at the other side?


good eye tim - that is indeed japanese on the front - katakana characters.

Here's what the back looks like - no labeling really, and that's as far as I can peel it back before the ribbon snags. You see those three wires? That's what I think are the ground, the left and the right channels.

Opinion(s)?

[repenttokyo]

that looks like the back side of the board... info would be printed on the other side, unless that's some japanese there - looks like it's only one screw can you take it off and look at the other side?

And a second pic

[tim eh?]

well the colours are right but who likes guessing with electronics...

that could be the main line out also - if that was the case and you spliced a line into it you would be able to listen to your mp3 player and the radio at the same time! but when you selected tape it should take just the mp3 player signal... plus maybe some (practically inaudible) line noise from the tape deck.

the proper way to do this is disconnect the tape signal and replace it with a line from the mp3 but if you just splice it in there won't be much difference.

am i making sense? i searched around quickly for some kind of japanese/circuit board translation but had no luck... is there any more printing on the other side of those white plugs? those plugs (for the ribbons) should come off if you want to explore some more, just be gentle of course.

is there a model # on that stereo?

[tim eh?]

ben, i just reread your first post... i'm surprised you are not replacing it seeing as the radio doesn't work either.

i found a used jvc tape head for $40 at a tv repair shop where i wasn't even a 'preferred customer' ... kicks ass man, and once the factory amp is bypassed i know for sure it will sound great. the speakers are awesome in this car dude, it's worth a better head and amp. plus a lot of heads esp. cd changer controllers can be converted to take a line in with an adapter you can buy for $10 on ebay.

cool thing about tape decks, nobody breaks windows for them.

[repenttokyo]

ben, i just reread your first post... i'm surprised you are not replacing it seeing as the radio doesn't work either.

i found a used jvc tape head for $40 at a tv repair shop where i wasn't even a 'preferred customer' ... kicks ass man, and once the factory amp is bypassed i know for sure it will sound great. the speakers are awesome in this car dude, it's worth a better head and amp. plus a lot of heads esp. cd changer controllers can be converted to take a line in with an adapter you can buy for $10 on ebay.

cool thing about tape decks, nobody breaks windows for them.

\the radio works fine, what doesn;t work is the shitty fm transmitter that attaches to my zune.

[tim eh?]

\the radio works fine, what doesn;t work is the shitty fm transmitter that attaches to my zune.

oh ok... yeah those things bite. fm radio rules tho.

a proper transmitter would be great for practical jokes at work, but they are hundreds of dollars and need more than a couple AAs.

hopefully someone can tell you for sure, but you aren't sending any major currents from your player, or from the head. it's only if you jack into the power supply or main ground that you will do any damage to anything...

[repenttokyo]

Ok good news - i wired it up and went out and tested it, and it works.

however, even with bass and treble turned all the way down and the zune on 1 for volume, it's massively overdriving the system - any idea what i did wrong?

[attack eagle]

how is it working exactly?
On tape mode?
on CD mode?

[repenttokyo]

how is it working exactly?
On tape mode?
on CD mode?

i don't have cd. It goes into tape mode bc I followed the instructions above.

[tim eh?]

i don't have cd. It goes into tape mode bc I followed the instructions above.

so in tuner mode you can't hear the zune?

what happens when you play with the L/R balance on your zune?

[repenttokyo]

so in tuner mode you can't hear the zune?

what happens when you play with the L/R balance on your zune?

zune doesn't have l/r balance, and I can't get the deck to shift back to tuner once I have tricked it into tape mode.

[repenttokyo]

figured out why it's overdriving - the preamp for the tape head is boosting my mp3 player's signal, which is already at line level. Only way around this is to reduce the mp3 player audio signal to below line level using a cap and resistor system.

[tim eh?]

figured out why it's overdriving - the preamp for the tape head is boosting my mp3 player's signal, which is already at line level. Only way around this is to reduce the mp3 player audio signal to below line level using a cap and resistor system.

or change your splices and put them after the preamp. can you see the preamp or are you making a (probably correct imo) assumption? you would get better audio quality by skipping the preamp.... reducing and reamplifying all the time leads to a lot of hiss (which you don't generally notice in a car even a quiet one)

[repenttokyo]

or change your splices and put them after the preamp. can you see the preamp or are you making a (probably correct imo) assumption? you would get better audio quality by skipping the preamp.... reducing and reamplifying all the time leads to a lot of hiss (which you don't generally notice in a car even a quiet one)

Looking around the head unit, I can't really see an easy place to splice in after it. Looks like this might be the end of the line for my experiment.

[tim eh?]

Looking around the head unit, I can't really see an easy place to splice in after it. Looks like this might be the end of the line for my experiment.

you could still splice into the line out of the head. you'd have to do 2 pairs for fronts and rears.
then you could just switch the head on and control volume with the zune.

sorry it's not working out man...

i understand the stock vibe, really, but an aftermarket head doesn't have to stand out ya know...

http://www.bimmernut.com/forum/attachment.php?attachmentid=5916&stc=1&d=1220634309

the PO had put a silver head in there (wired it bad too), now that was really ugly
http://www.bimmernut.com/forum/attachment.php?attachmentid=6394&stc=1&d=1229464635