Introduction: Connect an MP3 Player to a Tape Player
How to connect an mp3 player, or other stereo source, to a tape player in order to listen to the music.
Step 1: Materials
For this proyect you will need the following tools:
-A soldering iron
-A multimeter
-Headphones or stereo wires and plugs
-A tape player
Step 2: Dissasemble the Tape Player
You must dissasemble the tape player in order to get the circuit board.
This step varies with the model of the tape player so I won`t put any picture.
Step 3: Locate the Magnetic Head
You will find the magnetic head in the place you used to insert the tape.
The head must have three wires, one is the ground and the two others are for the right and left channel.
Step 4: Locate Where the Magnetic Head Connects to the Board
Follow the wires that come from the magnetic head to the circuit board. On mine it was a 4 port connector, it may vay with your tape player.
To identify what pin connects to each wire you can use your multimeter, by checking the continuity of the connections. I'ts usually represented by a diode in your multimeter.
Put a tip on where the wire connects to the head, then put the other tip in the connector. When it beeps the wire where you have put one tip connects to the point of the circuit where you have put the other.
Step 5: Solder the Wires
Now you have to cut the earbuds and peel the wires.
Stereo wires usually have a copper shield that must be connected to ground, left channel its covered with a white or blue plastic and the right one is covered in blue.
Now you have to solder it where the magnetic head´s wires connects to the board.
If you can´t locate it you can solder it to the head.
The ground cable is usally covered in black plastic.
On mine ther was 2 points for the ground, that are short cicuited. That's why I only have connected the shield once.
If you crossed the right and left cables it will work fine too.
Step 6: Finish
Now re-assembly the tape player. Connect it and press play, then connect your mp3 player and press play as well.
Adjust the volume in order to listen to it well, I recommend you to put your mp3 player the lowest you can.
What you have done it´s to make a shunt in the amplifier where you connect your mp3 as it was the magnetic head.
There´s a non destructing version of this, thats attach an earbud to the magnetic head, but it may be difficult and you will hear your music in mono. It will be good if you forget the CD in a party or something like that.
If you do that you should put your mp3 at the maximum volume.
Enjoy

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66 Comments
Question 4 years ago on Step 1
My car has a Cassette player, and i'm just wondering if it would work with that, I don't see why it wouldn't but it doesn't hurt to ask. Could you also wire it to a 1/8" Jack that you could then plug an AUX cable into? Thanks
7 years ago on Introduction
Looks great. I will be trying this on a tape deck with a bad head so a tape adapter would do me no good. Thanks for the help!
13 years ago on Introduction
I did the same sort of thing to an old AM/FM/Tape Sony boombox I had, but instead of cutting into the tape head and destroying the tape player, I found that it had a separate tuner board for the radio. Looking at the cable connecting it, I found the ground, left, and right channels coming out of the tuner. I spliced the left and right through a double-pole-double-throw toggle switch and also mounted an AUX input jack next to the headphones jack. Now I can flip the switch to AUX to listen to mp3 player or computer (I also used it to play Xbox on my old TV) or flip it to Radio to use the radio. Also, the amplifier for the tuner is designed for line-level whereas the amplifier for the tape is designed for a tape head, connecting to the tape head introduces more distortion whereas the tuner input sounds really clear.
Reply 11 years ago on Introduction
@pfmia: Connecting to a LINE level is the correct way to go... Radio tuner usually has close to line level; on the other side, the magnetic head has a much lower signal level, and it is NOT it´s only disadvantage: Magnetic Heads need a large equalization (like the old magnetic phono cartridges). THAT IS THE REASON connecting to the head will get distorted, badly equalized sound!!!
CalProgrammer1 has it ABSOLUTELY RIGHT!
It is WAY better to find Radio or Line level points in the circuit, in that way distortion is avoided (provided the cell phone or MP3 player volume control is NOT pushed too high), and a PROPER, flat equalization is obtained. Head level is too sensitive and not flat responding. Maybe tapping close to the VOLUME control of the boombox is an easier point to locate, in order to connect the pair of shielded cables to the switch and RCA input jacks (or the smaller 3 conductor 1/8" stereo jack, if you prefer. Best Wishes, Amclaussen.
Reply 11 years ago on Introduction
How do you determine which are the right, left and ground channels if you don't have a schematic?
Reply 11 years ago on Introduction
Ground should be easy, but beyond that you'll have to probe it. You can take a headphone speaker, tie one end to ground, and use the other end to find the audio signal. Once you find both signals, determining left from right should be easy (either play a tape recorded with only one channel or introduce a signal into one of the spliced wires and see what speaker the sound comes out of).
Reply 13 years ago on Introduction
Yeah is the same thing, you are right about the levels of distortion, but i haven't noticed it by keeping the mp3 at low volume. By the way I haven't destroyed the magntic head, so I can still play tapes.
It is nice to see that an Instructable written 3 years ago is still useful to some people
12 years ago on Introduction
really nice, I may try this one
13 years ago on Step 4
i have a timex radio clock and i wanna hook the the cord into the amp not just the stero cus some of my songs arent loud so i wanna be able to turn it up on the ipod and the radio
13 years ago on Introduction
hi ifound ur article and very interesting indeed, But i have 2 questions 1)when we connect the ipod/music player o/p directly to the head leads isn't it going to produce distortion as the input signal from ipod have considerable power where as magnetic head produces power in terms of uW (or signal voltage level of few millivolts) ,the distortiis casued by shifting of opearating point of PREAMP whic is conected immediately after the head unit. 2)like wise some people said using poteniometer will help reducing input signal ,but ifeel it wont be of much use....as they dont give clear demarcation of power limits. What if we solder the input after the preamplifier stage or at the input pins of Amplifier IC of the cassette player??? having tried the given method at my car stereo it aint did good ,plz let me know if something better comes in anybody's mind.thanks
15 years ago on Introduction
pfmia, thank you very much for the instruction. I followed your guide, and it worked ! but my problem is : distorted sound. 1. if i turn-down at lowest volume on the cell, and turn-up my car stereo volume, i got a very noticable hiss sound noise, and the distorted music still there but reduced. 2. if i put 1/3 volume on my cell, then the hiss reduced, but more music distorted. 3. if i put more than 1/2 volume on my cell, then i got a completely distorted music. 4. if i feed the cassette, but not plug the male cable to my cell, turn-up volume on car stereo and then touch the body cable, i hear "dep" from the speaker. what did i do wrong ? i just wonder, is there anyway i can do to normalize all this hiss and distorted sound ? is putting a stereo potentiometer / resistor on the cable will solve ? but i don't know the suitable size of the resistor. anykind of respond will be greatly appreciated, and i'm sorry for my broken english as i'm from asia country and i'm sorry too if this is not the right place to put my question. anykind of respond will be greatly appreciated, thank you in advanced.
Reply 15 years ago on Introduction
Thank you for your comment, I will try to help you. It seems that your cell, I think that is your mp3 player, saturates the previous amplifier, so you hear the distorted sound. As Jridley says you should put a resistor or a potentiometer in series with your cell, but I can't tell you about the actual values. I think that the best you can do is to put a potentiometer, the smaller you find, and try to find the suitable position to get the less distorted sound. I recommend you to put your cell at 1/2 volume, then put your car audio were you want and then try to adjust with the potentiometer. About the sound you hear when you touch the wire is normal, if what you have touch is the tip of the jack. If not maybe one of the solder joints is broken and you should check it. Some things you must check to avoid noises is to have good solder joints, shiny and clean, and be sure to connect the shield of the wire to the ground of the tip, and the ground of the music equipment. Also the shortest the wire the less noise you have. Luck and don't worry about the English, is quite good, I'm from Spain and I make mistakes too
Reply 14 years ago on Introduction
You put the potentiometer in series with...the mp3 player and head of the cassette player? if i'm using audio cables (left and right), do i buy two potentiometers?
Reply 14 years ago on Introduction
Well, the potentiometer has 3 leads. Two of them have a fixed impedance between them and the other one shows a variable impedance. You should connect one of the fixed ones to ground, the other to the mp3 player and the last one to the magnetic head. You should buy two potentiometers, one for each channel. The ground is very important, with a good connection you will have a very clean sound, if not you will have lot of noise
Reply 14 years ago on Introduction
I attached the two potentiometers like you said. When I attached the ground to the potentiometer, a lot of the distortion went away, but the a little static/hum remains. Any other ideas?
Reply 14 years ago on Introduction
Some hum will be normal. Try to minimize the length of the wires and use shielded wires, connect the shield onf the wire to the ground in both ends of the wire
Reply 14 years ago on Introduction
also, how important is it to used the ground between the mp3 player and the circuit board?
Reply 15 years ago on Introduction
thank you - thank you very much indeed. i'm very happy to receive your reply, and your kind information. i will tell you my result as soon as i have tried your suggestion to put the potentio/resistor into the stereo cable. it's not the tip naked cable that i tap, but the cable body which is coated which make sound. so i will also check the solder joints and the grounding connection. i really appreciate your time to enlighten me. thank you once again !
Reply 15 years ago on Introduction
Try to chek the solder joints before you put the potentiometer, it seems that you may have some of them broken
Reply 15 years ago on Introduction
hi pfmia, it works - it works ! i follow your instruction : "the smaller K-size potentio you can find" so put a 10K potentio between head-unit to the mp3 player connection, and the result : no hiss - no distorted music ! i'm happy now...:-) thank you very much for your kind reply and your great instruction. regards, reko