Need advice on <10W amp for computer speakers

[MtBiker]

I need some advice on how to go about building a very small low power amp for some actively crossed computer speakers. So opamp V gain and ? I gain. Go discrete? Use TO220 buffers? Looking to get 1-10W of power. Remember, this is 4 channels so size is important.

TIA

[Steve Eddy]

Originally posted by MtBiker
I need some advice on how to go about building a very small low power amp for some actively crossed computer speakers. So opamp V gain and ? I gain. Go discrete? Use TO220 buffers? Looking to get 1-10W of power. Remember, this is 4 channels so size is important.

If size is important, then I think the natural choice would be a power opamp such as the National LM3875 (the device used in the 47 Lab Gaincard).

se

[UrSv]

If you need 4 channels and it is for a computer speaker (usually associated with something else than single-ended class A or large budgets) I would try any of the TDA200X amplifiers like TDA2003V. They are reasonably cheep and they give that kind of output. You should be able to build 4 channels on a 100mm * 75 mm board if you think first.

/UrSv

[joensd]

hi,
for your power requirements it´d sufficient to use something like a TDA1519w (2*6W amp), TDA1521 (2*12W amp).
With a TDA 1554Q you even have all 4 channels in one chip.(4*11W)
for simple computer speakers that´s ok.
if you want better sound try "Overture Series": LM1876 (2*20W) or even ,like steve suggested, LM3875,LM3886.

[djdan]

You can use " car integrated amplifiers " like TA8210 or similar and supply with +12V direct from computer power supply.

[jackinnj]

For those making computer speaker amplifiers, the LM1876 is just the right chip -- 2 of these with a couple opamps used as high and low pass filters make an excellent device for powering a couple audax drivers.,<p>This lil bugger has a lot of feet (15), however. I used the same pad size as for the LM3875 which makes them close, but it shouldn't represent a problem. Just clip the image to MSPaint.