Old Car Stereo MP3 AUX Conversion

OOOww it's that time of the year when car boot sale bargains can be had and I can start filling the house with other peoples unwanted shite.. ahem, I mean priceless 'treasure'.

Last weeks bargain was this old in-car cassette player, boxed 'un all for £3!! It'd be a crime not to buy it for that price.  

It still has it's warranty card.  Where are Minachi now I wonder?

I do love a bargain! It was manufactured by a company called Minachi in Japan in around 1972 - the same year as my car.  It's pretty basic, there is no auto reverse or rewind on it but the power light is purple, psychedelic man!

Lashings of chrome

The main reason I went for a tape player over an old radio is most cassettes were pre-recorded in stereo so most players have stereo sound which is good for what I have in store for it, namely an iPod conversion.

The first task was to take the thing to bits, taking things to bits was a pass-time of mine as a kid, torches were a personal favorite for some reason and it is still a running joke now with my dad, if his torch 'mysteriously' stops working I get the blame.

I located the playing head and traced the wires back to the circuit board. There are only three, left channel, right channel and earth.

Located the playing head

Next job was to attach wiring for a 3.5mm headphone socket.

Solder on the connections.

I'm not the best solderer but it's fairly neat.  I used some fairly hefty wire to reduce signal loss but I doubt it makes much difference on a player like this. The last step was to drill the metal casing to make a hole for the AUX jack. 

Finding a convenient place to mount the jack

Finding a convenient spot was fairly straightforward.  I did not want to see the jack so it's on the back and I'll run a headphone extension lead with a panel mounted AUX jack else where, maybe hidden in the glove box or center console. 

Now of course it would be far easier to use one of those tapes that has a headphone jack on the end of a lead attached to connect up my iPod but where is the fun in buying a readymade solution!

I tried it out and it works OK but you need to insert a cassette in the player for it to operate as there is no on/off switch.  I cant remember the last time I used a cassette, so could I find a one in my house? balls... I had to ask a mate and lend one just so I could try it out.  Years ago I had dozens.

I don't fancy using cassettes every time I want to plug in the ipod and then I might as well have just bought a plug in adaptor and be done with messing around. I do not tend to give up that easily though.  Whenever you bung a cassette in it switches on, there must be a switch somewhere.

Found it!

When the tape gets pushed in the mechanism slides backwards and pushes two contacts together mounted to the frame of the tape deck which is a nice straight forward design. 

I found some appropriate gauge wire (from a disused transformer) and proceeded to strip that back and use it for an externally mounted on/off switch. 
I drilled another hole in the case for the wire to exit which I knotted, so it cant be accidently pulled out, then de-burred and taped the hole up, so there are no sharp edges, finishing with sealant.   I also tidied some of the wiring inside the unit as the solder was getting ropey after 40 years. Hopefully now the circuit can be made without the need to insert a tape!  

Nearly there 

You can now see the two parts of loom in place.

Going back together nicely

I whiled away a few hours on this but as you put it together the evidence of the time spent working on it is hidden away. 

Rear of unit

There we have it, a new AUX socket which will accept an iPod or other MP3 player and a remote on and off fly lead to avoid having to insert a tape.  I think I'll probably mount an AUX connection in the center console and have a power switch next to it which will activate the port or maybe you can get some kind of headphone jack that works like a switch when you plug in combining the two?  

Anyway from a casual glance you'd not even know about the mod. The bonus is that it still plays tapes and when you plug an iPod into the AUX port it senses that and cuts out the sound from the tape even though it continues to run.  Really pleased, the radio was £3, the 3.5mm stereo jack was about £1.30 and the wire was all knocking about in drawers for free so I got an authentic 1970's stereo which plays MP3 (in stereo!!) for under a fiver!

Thanks for reading!