Ok, i have done some research on this before i posted. there have been others that want to build an amplifier for ipod, phones, etc. i want to do something similar but more complex. there are thousands of amplifier circuits on the internet. ill tell you want im looking for and hoping i can get some help from the experts!

-input: cell phone, ipod, mp3 player.

-stereo in/out

-preferebly runs on a 12 sla battery but not necessary.

-volume, bass and treble controls(bass boost is a plus)

-simple as possible without sacrificing quality

i dont know how many watts i need, but would like it to shake the floor at full bass/volume(depends on the speakers i pick out)

thank you all very much!

im not sure what speaker impedance im using yet

 

You will not shake the floors with an amplifier powered from only 12V.
You need an amplifier with an output of at least 50W RMS per channel for at least 2 channels. The speakers need to be big enough to produce bass frequencies. The speakers do not produce the power, the amplifier produces the power.

If a speaker is 8 ohms then a single-ended amplifier powered from 12VDC drives it with about only 1.5W. A 4 ohm speaker gets only 2.7W. A bridged amplifier driving a 4 ohm speaker produces about 10W.

Use a power supply of 62V to power a single ended amplifier that will produce 50W into an 8 ohm speaker.

Why do you want to use a battery?

 

the battery is for portability, but not necesary. ill just use mains. can you recommend a circuit that is close to what im looking for? ty

 

i did some more searching. what are your opinions on these 3 circuits:

http://www.zen22142.zen.co.uk/Circuits/Audio/32wamp.htm

http://www.national.com/mpf/LM/LM1875.html#Overview

http://home.roadrunner.com/~randylinscott//nov99.htm

it would be nice if they had bass/treble/volume adjustments. i dont know too much about audio circuits, so thank you much!

 

The datasheets tell you the output power:
1) The TDA2050 produces 32W into 4 ohms or 18W into 8 ohms. Most home speakers are 8 ohms so it will not be loud enough.
2) The LM1875 does not have enough power since its output is only 20W into 4 ohms or 8 ohms.
3) The TDA1554 also does not have enough power since it produces only 10W into 4 ohms for each of its two channels.

An LM3886 produces 50W into 8 ohms with very low distortion.
Tone controls are part of a preamp circuit that you need to drive the power amp.

 

Thank You! the lm3886 is a very simple circuit! now i just have to find a suitable preamp circuit.

 

Thank You! the lm3886 is a very simple circuit! now i just have to find a suitable preamp circuit.

Here is a website with many good audio projects including bass and treble tone controls etc.: http://www.sound.westhost.com/index2.html

 

im looking into the lm3886. have a question. on the datasheet @ http://www.national.com/ds/LM/LM3886.pdf im trying to figure out the Rm value on pin 8. on page 8 is a formula for the value. im lost, could someone please offer some advice?

 

Pin 8 must be -2.6V from the output DC voltage with a current of 0.5mA for the IC to mute. It is fed from the negative supply so the formula for Rm is (-VEE minus 2.6V) divided by 0.5mA.

 

ive been doing some more reaseach on the lm3886. i like how simple the design is. i found 2 circuits that are fairly similar. one is a little more complex than the other. does more complexity mean better performance or quality? the first link has a few more components and different values.

http://diyaudioprojects.com/Chip/LM3886_CA/F01-LM3886-chipamp.png

http://www.circuit-projects.com/aud...inclone-2x68-watt-full-amplifier-project.html

 

The second circuit is designed by idiots because it is missing the important parts recommended by the manufacturer.