Portable Speaker For Mp3 Players, a beginner-level project

[juhoeric]

I made a portable speaker meant for use with MP3 players. It's just a TDA7052 amplifier with stereo-to-mono mixer built into some old PC speaker. Great for beginners, very simple to build and has a great sound compared to the overpriced portable speakers found in stores... But of course the sound depends on the speaker you build it into.

Pictures and schematic at my blog at: http://juho-eric.blogspot.com/2011/09/port...mp3-player.html

Good luck!

[karen]

here is a factory in china.









I stupid spammer that think I can make sale this way.

Cleanup crew to Aisle four, please

This post has been edited by Geek on December 31, 2011 05:19 am

[CWB]

e-ticket punched .
please drive forward , don't look back ... and have a nice day .

[Geek]

Neat project, Eric! Thanks!

[VenomBallistics]

good start into the field.
I did similar stuff early on and quickly evolved into some nasty audio producing machines.
now you need a little more in the front end to give yourself an equalizer before sending the signal off to a low pass, band pass, and high pass filter array into a triamp arrangement.
gotta evolve and progress .... right?

[tekwiz]

Good job.
Have a browse on eBay using the search term "audio amp module". There are an amazing number of amp chips available at very low prices.
The LM3875 is one of my faves...under $5 apiece & 50 watts max output, with only a few extra components needed. These can also be used as drivers for a transistor power stage.


Now you'll have to build a stereo version. This can be done with a single computer speaker, too.
You would use 2 amps...one for bass & a stereo unit for the mid/tweeters.
Mount the tweeters on the sides of the speaker & it'll produce not bad stereo sound from a single small enclosure.


BTW: Watch it, as building your own amplifiers is addictive. I keep buying the newest amp chips while still having some of the last 'newest' amp chips.
Now I've got more than a dozen types on hand, ranging from 500mw to 50W.
I hope my descendants appreciate them.

[VenomBallistics]

tell me about it tek
another one to study up on is the LME49810 and LME49811 driver chips.
add a bias generator and a wicked output stage and fasten your seat belts for up to 500+ watts of stunning high end audio...
but our new friend here would do well to stick with the small stuff for a bit till he gets rest of the signal chain doped out.
seeing 5 - 20W going poof sucks a whole lot less than the fire works involved with a +100 / 0 / -100 V fed animal

another cute trick with acoustics is to do as tek said with a pair of good wide range speakers and wire them out of phase.
what happens is they cancel eachother out at the enclosure and cannot really be heard until the sound reflects off the walls.
the arrangement take a good bit more power to overcome the drop in efficiency but it does perform admirably