Calling all experts (or at least the moderately skilled): mp3-car audio amp project

[ki6fzb]

Hello,

My car currently has no stereo, so in lieu of buying a stereo, I'd like to build an amplifier circuit to connect my MP3 player to my car's speakers.

The obvious problem is that I don't know how!

I am very new (about two months or so) to circuit design and building. I know my basics (Ohm's laws, EIR, PIE equations, etc.) and understand the basic concept of a transistor amplifier. Beyond that, I'm a bit fuzzy.

I have perused around and using a MOSFET IC (such as one of the TDA series ICs) sounds like a good way to go, and I have once stumbled upon a 4 channel IC somewhere (don't remember where, though!). I've looked at many schematics, and have gotten a vague clue how to go about it, but I still don't understand enough to design my own circuit, or even really to use one of the ones I've come across. As I understand it, a car provides 12VDC, but many of the schematics call for 20VDC and up.

I realize my query is a bit open ended, but any help is appreciated, and as my research into this continues, my questions will become more focused.

Thanks!
Stuart
KI6FZB

 

[vne147]

I recently completed a project where I built a mono amp that was powered by the 6V system of a 1957 VW Beetle. I'm going to revive the thread a little while from now when I post some pics of the finished project. Anyway, what I ended up doing was using a DC-DC converter to boost the voltage from 6V to about 15V. National Semiconductor has the pretty awesome and free software called **broken link removed**. If you input your your associated parameters like input voltage, output voltage, and current draw it will spit out a list of appropriate components and then even generate a shematic complete with a BOM. I suggest you check it out. As for the amp itself, there are many options. I used a TDA2003. I think they make a similar stereo version. Not sure about 4 channels though but I'm sure someone here does.

Edit: Here's that thread I was talking about:

https://www.electro-tech-online.com/threads/audio-amp-component-selection.100196/

You may find it helpful.

 

[ki6fzb]

VNE147, thanks for the tips!

Another question, would a single stage between the MP3 input, and the speaker outputs do the job, or would I need multiple stages?

 

[vne147]

I think that all depends on how much amplification you plan on having but I'm not certain. I don't have very much experience in building amps at all. Aside for a 1W amp IC that I once used for a project with sound, the thread I linked above is my only experience. There are probably much more qualified people here to advise you on that. Sorry.