how to make a portable mp3 amp from old computer speakers

have you got a pair of old computer speakers lying around that you dont need?
want to make a decent iPod/mp3 amp?
these speakers are powered via a PP3 9V battery

materials:
speakers
snap on clip for 9V batter
9V battery
audio source

tools:
soldering iron and solder
screw driver
wire cutters/teeth
wire stippers/teeth

Step 1 Disassemble speakers

your speakers might not be 9V, if there not you could possibly use AA batteries in series in aholder or use a gel cell, bit heavy though.

disassemble the speaker with volume and power input, unscrew it from the back, there should be a transformer attached to the back, this is what takes the 230V (110V) down to 9V or the working voltage for your speakers.

on the transformer it should say the primary and secondary voltage, the secondary voltage should be lower, 9V hopefully, if it is not 9V you may still be in luck, if it is 3V use two AA batteries, if its 6V use 4, if its 12V use either 8 AA batteries or a car battery or gel cell battery, look online for one.

however, if you want, you can put a batter inside if you have room, or outside if you dont, and put the speaker cases back together.

Comments

[Tv1996]

can you make this solar

[K'nexFanatiFreek]

if you have a big enough panel, but ya might wanna put a inductor on it so that the speaker isn't broken by rapid voltage changes.

here's a video that explains in inductors: http://www.youtube.com/watch?v=STDlCdZnIsw

[FriedRiceFreak]

I am pretty herp-derp when it comes to electric numbers, but could you use 6 1.5v batteries? because I have a 6 AA battery holder, and they are rechargeable too.

[K'nexFanatiFreek]

yep, but rechargeables might give you less performance as rechargeables that are "1.5V" are actually 1.2V, because the chemicals that are needed to make the battery rechargeable

[jwarburton1]

I have the same set of speakers as you, but cant remove the nut holding the amp board in place :/ WHAT DO I DO?!

[Blubber300]

Would this work if I just left the power supply in and wired it into this?

[CDAWWGG]

You should use a dry cell holder and AAs or C's because they will last longer in the long run. I tried this with some old boston acoustic speakers that got destroyed when my workbench caught fire >_< (now made of concrete..the more you know *ding*) and I needed an amp but didn't want to order parts for a chip amp. Good instructable.

[liamhickey]

batteries are dc.. so soes it matter if the power supply was ac?

[tomtortoise]

on my board i saw 4 diodes in a rectifier looking like thing so i believe you can power the board with a DC battery

[Whales]

Tried it, on a few sets of speakers, So if you are wondering on quality, it really depends on what speakers you use. The better speakers, the better sound. Enough said.

[Valgarn]

And, why did you take it appart? wouldn't it be easier to just take the transformer out and replace it with a battery?

[odavidson]

 In retrospect i should have replaced the transformer with a battery, but these speakers were destined to go in a backpack.
With mine a freshly charged 9V battery lasted me about 5 hours, at about 1/4-1/2 volume. It depends on your speakers but in normal use they shouldn't draw much current.

[Valgarn]

won't you drain the 9v battery like, veeeery fast?
my transformer says: O/P:9V-1A
It's working perfectly though, sound quality is as good as with 230v from the wall^^

[magnam]

hey, i have similar speakers as you, i removed the board from the speakers,
and i connected 9volt battery as power source, and i conect headphones to headphone jack.
it works, but audio quality is very poor. can you tell me what might be the reason?
my speakers are old so maybe its somthing wrong with my board???
hlp pls.

[deathnote_213]

man is it running in 9v battery ?? we have the same speaker but my little brother broke it but my sure the components inside is still working please help me i like to convert it to portable speakers that i can bring in my bag... haha...LOL 
but i'm serious hehe.....great thinking keep it up....

[Foaly7]

Could this make a voice changer that someone whispered into loud as normal human voice?

[Da Nugesta]

who removed my comment?! i don't mind but whY?

[Da Nugesta]

(removed by author or community request)

[Da Nugesta]

But they don't have that bad quality sound. its not top quaility but enough to bear with

[sherwinrulzz]

well i tried this on a really cheap ($4.99) dollar speakers ...just for trial run ..and it worked !!!! except for the sound clarity ...which is really bad cos of the cheapness ...i wanted to know if the same thing would work on pair of travel speakers (just connecting the PP3 clip part) cost i just wanna put one 9v battery and not may AAA size batteries .... thanks and great instructable

[HeWantsRevenge]

if u had idea for a casing ud prolly get a perfect score...noone besides u has thought of adding a power source to the speakers other then an ipod or whatever...great instructable buddy XD

[Phil B]

I wanted to play Podcasts over my MP3 player while working in my garage. I just took a pair of old computer speakers and plugged the 1/8" male stereo jack from the speakers into the player's earphone jack. For power I used an old voltage transformer. Mine happened to be AC, so I added four diodes configured as a bridge rectifier and added a 1000 mf capacitor for smoothing. It works well. Had the voltage adapter been rated at too high a voltage, I could have dropped the voltage with diodes in series at 0.6 volt drop at each diode, or I could have added an LM317 variable voltage regulator, or two sufficiently high wattage resistors with a tap to give the proper voltage.

[Wolf Seril]

People have been doing this on instructables for years with TV speakers, but this seems a lot better since there is an amp board in the computer speakers.

[mrbob1000]

that is sweet! hows audio quality?

[odavidson]

quality is actually really good, i can even hear the bass guitar in songs!