| BubbaGump |
| I need to build a stereo audio amplifier that has an output power of around 2 to 4 Watts per channel for an 8 ohm driver. If anyone has any information on how to build this, what IC to use, the external parts, or a schematic, it would be greatly appreciated. I think I can find a good IC, but I don't have any idea how to design a circuit for it. Thanks. |
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| DJ Exprice |
| 4 watts? BAH HUMBUG! :D Check out my website's projects section and look at the TDA2030 design. There's a 10watt-er for ya! :D Hope that helps! |
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| abid_rehan |
Alternately you could try TDA2002, very simple chip and good 8watt output.
simple 5 pin IC. |
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| BubbaGump |
| Does it matter if my speakers are only rated for 4W max? |
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| mr.duck |
| It should be possible to reduce the power supply voltage to limit how much power can be delivered to the speakers. |
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| BubbaGump |
| Thanks for all the help. That TDA2030 looks good. Could someone tell me exaclty what I need to do get an output voltage of 4W or a little less? |
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| BubbaGump |
| If I used the TDA2002 would it be stereo? Can someone show me a schematic for about 4W output power per channel? I am new at this, so please bear with me. |
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| mr.duck |
Look at the data sheet for TDA2030. It will how a typical schematic that you can just copy.
On page 4 see "output power vs supply voltage". The 1st graph show that with a +/-10v supply, the amp can deliver 4 watt into 8 ohms with 0.5% distortion.
The amp can work from +/- 6v supply if you really want to limit output power. But +/-8v should be fine. |
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| BubbaGump |
| Yeah the TDA2030 would work, if it had 2 channels. Is there a way I can make it two channels? I doubt there is, so can anyone refer me to any other IC's with 2 channels? |
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| SpittinLLama |
Seach National Semiconductor for a cheap, easy amp in this power range. The LM4954 comes to mind. It is single channel but just get two of them and make a 2-4W amp using batteries if you want. You can get a battery holder from Radio Shack for some AA bateries and that can be your power supply. This is one of the easiest ways to do it. Will sound OK and work fine. Something you might want to look into.
-SL |
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| ! |
It doesn't get much easier than LM4752
Advantages
- Minimal pin count
- Uses Single Rail Supply (but then requires output coupling)
Depending on output power, even a spare ~ 12V/1A wall wart could power it
- Fixed Gain, minimal parts needed
However, with this or many other chips, I suggest you not build for "4W", instead build for a little over 10W (higher supply voltage) so you get that 4W before you're in an area of quickly rising THD. Typical 10% THD @ rated power is not a place you want to be. |
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| cpemma |
The TDA2004 is another pleasant little chip that runs fine on a single-rail 12V supply and is already a dual (stereo or bridge) amplifier. The datasheet will show circuits.
The disadvantage (?) is 11 pins (well, it is stereo) but tbh, if I were in your position I'd look for a kit including the ready-made PCB; there are many that fit your requirements from Velleman et al.
As said, don't look for a 4W limit, that will include anything up to 20% distortion. Just go a bit higher and keep the volume off maximum. |
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| DigitalJunkie |
One other possibility,the TDA7350.
+12V supply,each chip has 2 channels (2x 10W) which are bridgeable to 20W per chip. Low parts count,and it sounds fairly good,IMO. |
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| stahlight |
Well for an old school solution, you might try the LM1877. Is rated for 2-4 W/ch and has two channels in one easy to use 16-pin DIP. I am a fan of this chip, was my first stereo power amplifier project =)
http://www.national.com/pf/LM/LM1877.html |
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