Need a simple amplifier circuit!

[yellowblood]

Hey all..

I have with me, a couple of old philips stereo speakers that came with an old telivision. After getting a new TV(which does not have a built in amp), these speakers have become useless so I'm wondering if there was a way to use them with my cell phone\computer\musical keyboard using an amplifier.

I have attached a couple of pics i took of the speakers and the only specs given on them (they came in the same box as the TV with no separate manual or rating sheet)





I just need circuit that has a 3.5 mm(or similar) jack on one side and gives the stereo output with these speakers.

Please help!

 

[audioguru]

The speakers look like small rear surround sound speakers that use low power and have no bass frequencies and no high frequencies.
there are hundreds of stereo amplifier ICs available. I guess 4W per channel should not destroy those tiny speakers.

 

[Vizier87]

LM386 would have been okay, wouldn't it, AG?

 

[audioguru]

LM386 would have been okay, wouldn't it, AG?

The output power from an LM386 amplifier IC is only 0.45W into 8 ohms with a 9V supply.
A cheap clock radio has more output power.

 

[Vizier87]

I thought it's an audio amplifier? You'd prefer.....?

 

[audioguru]

There are hundreds of audio amplifier ICs available. Most have much more output power than a little LM386.

 

[Dragon Tamer]

wouldn't a LM380 work? (and i have my own qq, would hooking up the outputs of 2 386 amplifiers increase the output power if one is an inverting amplifier?) Or... if you really want to have fun you can use an LM3886 and watch your speakers catch fire. (don't do that it's dangerous)

 

[audioguru]

would hooking up the outputs of 2 386 amplifiers increase the output power if one is an inverting amplifier?

Not if the speaker is 8 ohms.
The datasheet shows that it runs out of output current driving 8 ohms with a supply that is more than 9V so a bridged amplifier that has double the output current will just make more heat instead of more output power.

 

[Dragon Tamer]

okay, thank you that explins why my breadboarded circuit did not work

 

[joe_rocket]

Projects - Audio

10W Mini Audio Amplifier

 

[audioguru]

The "10W" Mini-Amplifier is a joke.
With a brand new 9V alkaline battery its output into an 8 ohm speaker is only 0.9W at clipping, not 10W.
Its output is 10W into 1.6 ohms when its supply is 15V.

 

[joe_rocket]

well, I am just now trying to learn circuits and electronics and searching for items that might help me build what I'm looking for i found that site..
just trying to help.

 

[audioguru]

well, I am just now trying to learn circuits and electronics and searching for items that might help me build what I'm looking for i found that site..
just trying to help.

I fixed many projects on that site (Electronics-Lab) but I can't fix them all because the bad circuits keep going there.