Modified MP3 player system on the cheap - mains/battery

bacteria · Post by **bacteria** » Tue Jul 01, 2008 6:34 am

The MP3 player I modded a while back has been playing constantly for months, but is not as good as it was. Went to a car boot sale, got a 1Mb MP3 player, its about 3cms x 2cms and was sealed in a metal covering, with no easy way to get into it - anyway, used my dremel and metal cutting circle; took a few minutes, managed to hack it off.

Connected the system to a set of speakers, nothing; used the smallest mylar speakers I had, barely heard much; so used an old amplifier from a cheap pair of speakers (takes 4.5v) and rigged it up. Soldered wires where needed, got the system going, with some nice bigger 8 Ohm speakers as in the pic. Total cost Â£4 as I already had the speakers and the amplifier was removed from some older speakers which didn't work too well.

Works great! Inside the MP3 player, was a tiny 4v Li-po battery, I removed the battery and hooked up the MP3 player to the 4.5v batteries.

In the case, I cut out holds for the volume control of the old amplifier, and a hole for the USB connector for the MP3 player. I used an old jewelery case from something I gave my wife years ago - box was right size, I just needed to trim off a little of the unused mobo from the amplifier to make it fit snugly.

No idea how long the batteries will last before needing changing, I may well put in a power supply instead to drive the system at some point.

Pics:

Took me a few hours today to complete.

Post by **bicostp** » Tue Jul 01, 2008 9:10 am

Nice! It definitely looks better than the old MP3 boombox.

Are those Realistic speakers? Those were the days... Back when Radio Shack made decent stuff. (Now they're the poor man's Sharper Image.

)

bacteria · Post by **bacteria** » Tue Jul 01, 2008 10:26 am

No idea what the speakers are. Last week, my parents gave them to me as they were going to ditch them. I have other sets of speakers too, these are havy but quite good audio quality.

Yes, far better than my last one!!

bacteria · Post by **bacteria** » Wed Jul 02, 2008 5:09 am

Batteries only lasted about 20 hours (the MP3 player barely takes anything, but the amplifier does), when the voltage gets under about 3.7v the MP3 player cuts out. I therefore did a further mod to this project - the system can run off batteries now, and mains. I used a TI step-down regulator, outputting 4v; it was the one I used on my last MP3 project. All works. If I want to play the system on the move I can with batteries, or mains for permanent on. If I want to make the system completely portable in the future, I have plenty of space on the lid to put some mylar speakers!

As you see, the old jewelry box is the ideal size - 15.5 cms x 11 cms.