12v stereo amplifier circuit

Have a look at the TDA1562 from Philips, it is not that complicated and will give a reasonable amount of power

martin

The LM386 is perfect for this; its cheap and available. See National's website for application circuits. You need 2 of them for stereo.

Luhan

Hi-

If I had to do the thing as painlessly as possible, I would visit TI.com, Linear.com, Phillips Semicondtor, Newark Electronics, Digikey and select a 2W - 20W IC amp. TI will send overnight 2 free samples for a sign up. Once you have the part you want, I would then parallel them up to get as much power as needed, up to several hundred watts. Each of the IC's is individually protected internally by current-limiting and thermal shutdown. If you want 200 Watts peak, then you might need to have about 10 of them in parallel. Each amp would need to be isolated from the speaker by 10 ohms or so. I would also use an additional amp (same part) at the input to drive the inputs of the power-producing IC's.

If on the other hand you want to make a statement, I would use a transconductance type discrete amp which will easily run several MHz of bandwidth and is rock-stable, I have used these to drive voice-coil motors at 1KW and 5MHz, and the same toplogy to drive the cathode of a hi-res CRT up to 30MHz at 120V p-p. The transconductance-type amp uses drain-output so the output load is driven right to the rails. You will have to do your own protection circuits but the low-noise and fidelity is unbeatable. The same circuit may be expanded by paralleling up to about 10KW, enough power to drive the antenna of a small AM radio station.

Henry Wilson

Stephen T> Hi

In message , dated Sun, 6 Aug 2006, snipped-for-privacy@gmail.com writes

You DON'T put 10 ohms in series with a loudspeaker. More than half the output power would go into those 10 ohm resistors.

Depending on the music he listens to, I suggest a 10K resistor be used.

I think NonDigital meant to put 10 each 10 ohm resistors in the circuit to isolate the 10 amplifiersthat are being paralleled. 10 is likely to be more than what is needed but they won't end up with 1/2 the power in them,

At which point you are driving the speaker with ALMOST as much power as if you used a 20W amp!

Most all amps are limited by their supply rails in how much voltage they can swing across the speaker.

Tim.

You need to bridge two amps to get any kind of power from 12V, allthough you could also use a DC/DC converter. The most you can get from a normal amplifier is almost 2 watts at 8 ohms and 4 watts at 4 ohms. Bridged, about 4 times these figures.

greg