I've featured the finished product on my home website Furocious Studios
Thanks to those users who have gone before me unknownuser2007 and HappyDad their instructables were key in pointing me in the right direction.
The inspiration for my project actually came from the guy who installed a 7 inch Tablet PC into a Hitachi ghettoblaster to achieve a Boombox PC. Gutterslide And now with the advent of the iPod Touch and several knockoff versions of the MP3 player...hmmm consider the possibilities!
Don't electrocute yourself! If you don't know anything about electricity then Stay Away! The warning on the cover of appliances about electrocution is there for a reason. You can be shocked and even killed x_X I haven't been shocked on this project but I don't go poking around where I shouldn't be. If you are getting jolts or blowing fuses that is a sure sign that you have no business messing with electronics. Consider yourself lucky you could be dead.
Step 1: Choosing Components
Selecting a Boombox
I found my boombox on ebay. There you have a bit of a selection. I also kept my eye open for 2nd hand shops, flea markets and yard sales.
1. I was looking for a boombox that had Aux Inputs just in case modifying
the tape deck didn't work out.
2. I payed particular attention to the ends and face of the box to make sure
there would be room to add the additional jacks and ports for my mods.
3. I wanted a boombox that could put out some decent volume. EQ wasn't as
necessary because most MP3 players have presets.
4. I was looking for a King of Boomboxes or at least the classic look.
5. Lots of chrome and lots of buttons and lots of features!!!
6. I was looking for a box with VU meters but those can be added later so
that wasn't as important.
Selecting an MP3 player
I looked for deals online. I ended up with a refurbished player for a fraction of the price for one brand new.
1. I had to keep in mind that I was going to install the MP3 player in the Cassette Deck
and make it appear as if it were a cassette in the window. So I had to choose an MP3
player that had a landscape orientation.
2. Most of the functions needed to be on the front of the MP3 player or I was going to have
wire displaced buttons to somewhere on the front of the boombox. The more buttons
to move then the more chances I would singe the circuits on the MP3 player (MP3
players have a lot of micro circuitry that is tricky to solder with clumsy fingers like mine).
Finding the bits
I made several trips to Radio Shack and ordered some buttons and things at sparkfun.com Look around online there are lots of places to buy components. Best of all many of the components I scavenged from other electronics I had previously. I'm a pack rat so I managed to save a lot of money on parts.
Step 2: Goodbye Cassette Player?
The first order of business was to carefully remove the cassette deck keeping in mind that I might need to re purpose some of the parts. The green arrows show where the wires connect the tape head to the circuit board. I thought it would be nice to use the wires with the 3 prong connector to attach the headphone output to the board...ah but to a blank spot elsewhere on the board.
Step 3: Power to the Tape Deck!
Initially I soldered the circuit closed so that it would power up immediately when the Tape Function was selected. Perhaps I could hook my MP3 charger where the Tape Motor was? Later I abandoned this idea and de-soldered the connection when I figured out where the main power was for the boombox. Now when the Tape Function is selected the boombox is essentially switched off.
Looking back with a little more research I could probably find a way to disable the cassette amp, still use the clean tape audio inputs at the function selector, and run the charger off the power source that was originally for the motor.
Step 4: Disconnect the Tape Deck Motor
Step 5: Prep the Deck to Be Accommodate the MP3 Player
So I decided to permanently install the MP3 player inside the old cassette carriage. In order to retain functionality of the front of the player I had to cut a hole in the face of the carriage. Also I custom cut a slot to slide the MP3 player into position.
This solution provides the MP3 player with added protection and shock resistance. Also the inset position provides added protection from scratching the face.
I'm sure that ultimately this project seriously voids the warranty on the MP3 player.
NOTE: Particular care must be taken and painstaking attention to detail in order to keep the final product from looking like the hack-job that this really is. Your cuts must be exact! Use some sandpaper can be used to smooth the edges but be careful to not scratch the surrounding finish. I used a dremel to make the cuts. Be careful that no rotating part of the dremel housing comes in contact with the finish.
Holes must be cut in the cassette carriage and the deck to accommodate the plugs and side button wires of the MP3 player.
Step 6: Wire in the Jacks
On the other side of the board I tried to determine where to wire my audio on the Function Selector switch. I was going for connecting to the tape function bypassing the amplifier for the tape deck. Eventually I abandoned this approach and just cheated and wired up to the Aux Line Input RCA jacks.
It would have helped to have the repair manual for this boombox but I didn't get that until I had finished the project. If only I had been a little patient who know how it would have turned out. All my attempts to use the tape deck circuit resulted in underlying noise that was simply avoided by going for the Aux Line In. Perhaps I could have figured out how to not only disconnect the motor but also disconnect the tape amp it would have been different.
The early reason I decided to go with the Aux Line in instead of the Tape Circuit was I wanted to use the motor power source for the charger. That changed later along the way as well. Now the Tape Selection serves as a total power down for the boombox.
Here's an instructable that successfully uses the tape circuit to play and charge an iPod https://www.instructables.com/id/PLAY-AND-RECHARGE-IPOD-USING-OLD-BOOMBOX---Hints-a/
Step 7: Reroute Side Buttons to the Front of the Boombox
Now with a micro-tip on your soldering iron and use extreme precision to solder your button wires to the solderpoints inside the MP3 player. If you splash any solder or overheat the components you will soon be chucking your MP3 player in the trash or scrapping it out for parts. I experimented on a $11 MP3 player that I burned up prior to this step when working on the whole charger set up.
The best place to thread the wires is through one of the openings for side buttons you displaced in this installation.
Make sure you seal up the MP3 player again for added protection before you finish installing it into the deck.
By the way...the MP3 player is precisely lined up and hot glued into the cassette carriage.
Step 8: The SD Card Drive Dilema
Well I never did get that part figured out. Any help here would be appreciated. I checked and rechecked the wiring but never got my extension to work. I used a micro SD card adapter to go into the card slot on the MP3 player. I drilled holes in the connectors and soldered wires to run to a New card slot for the exterior of the boombox. Essentially this mod was an extension cable adaptor. I tested the setup. All the connections were wired correctly from the adaptor to the New card slot. But I couldn't get the new card reader to work before final install so I gave up.
My final solution was to hack open a spot in the cassette carriage and deck to get to the MP3 player card slot. Fortunately the Zen is compatible with an 8 gig card. Most MP3 players only allow a 2 gig. Needless to say that 8 gigs lets you store a lot of music.
Unfortunately the Zen I purchased was a refurbished unit. Not long after I started using it I had a miserable time updating firmware or loading anything on the actual MP3 player itself. This means I have to crack the boombox any time I want to add or change music.
Step 9: Charge!!! or Maybe Just Recharge.
WARNING: Testing the voltage on a boombox that is plugged in to an AC outlet can cause electric shock, serious injury, and even death! If you don't know how to use a multimeter chances are you shouldn't be attempting this type of mod.
The USB data lines from the MP3 player run directly to the new Micro USB port mounted on the end of the boombox. The power lines from the Charger go to the New switch so that power can either come from the Charger or from the New Micro USB port which can be linked to your computer to load music onto your MP3 player.
With the charger installed I do not have to have a computer to recharge your MP3 player.
Oh...the old tape counter...that is just there for cosmetics.
Step 10: Is That a Cassette Player or an MP3 Player?
Now sometimes you can glance at the Tape Deck and swear that there is a tape in it.
Step 11: Going Crazy!!! ...future Projects.
I am considering trying to figure out how to set up the MP3 player to run off of power from the box instead of the battery. To accomplish this I would probably use a 5 volt voltage regulator. However if charging causes an electric hummmm then running power from the boombox will probably do the same. So I will have to install a ground loop isolator (two audio transformers) in the audio lines.
I went on to modify another boombox. This time I used a Magnavox D 8443 and an iVO-Sound m1050 personal media player.
Installing the MP3 player displaced 5 buttons and a power switch which I relocated to the old cassette player buttons. All of these buttons being outside of the MP3 player cause a horrible ground loop problem. I tried a ground loop isolator but it cut out some of my sound as well. Frustrated I asked the question on the Instructable question area and figured out the best I could do to resolve this was change the power cord to a three prong cord. I still haven't changed the power cord yet. I am scrounging around for an old computer component that has a three pronged socket to replace the standard two pronged socket of the boombox. The two HOT prongs go to where the old ones were. The third prong the ground wire is connected to where the ground wires from the audio cables connect to the board on the boombox. Of course if you have an older house your power outlets may not be grounded so a three pronged plug wont do you any good. If that's the case then call an electrician and have your house properly grounded before bad things happen to your happy home.
My favorite mod is that I added LED VU meters under the left and right speakers. I got the LED kits ready-made off of ebay http://shop.ebay.com/merchant/hobbykitbg_W0QQ_nkwZQQ_armrsZ1QQ_fromZQQ_mdoZ For one of the speakers I had to resolder all the LEDs to the other side of the board to get the board to fit in such a tight spot. Unlike light bulbs LEDs are Unidirectional so you have to solder them back on so the electricity flows through the LED in the same direction as before.
This whole project has been a ton of fun troubleshooting and problem solving. Every feature you decide to add and every different component you use puts a whole new spin on how the project will turn out.
If there is a next project I will probably attempt install an MP3 player that I make from scratch that mainly plays SD cards and USB flash drives. Sparkfun.com has several kits I could use to do this.
...after having said all that...For anyone who attempts a project like this I wish you the best of luck!!! Have fun!!!!