Computer amplifier.

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Hello, I was wondering if you guys had any suggestions on an amplifier circuit that I can build for an upcoming computer speaker set that I will be building. TIA for any input!

P.S. I've read on this section of the forums and someone was raving about the sound from an eight-watt amplifier...eight watts? Wouldn't you need more? I'm asking these questions because the last thread that I posted did not receive any replies! Now, I'm getting close to building the speakers and would be forced to buy a plate-amp because I would be left out alone in the rain again. Yes, I am new to building amplifiers in general and need to start somewhere. Also, I have basic knowledge of circuits, have used ICs, resistors, caps (no transformers yet), and such with some breadboards but, am bored of making blinking LEDs and want some DIY audio!
 
The simplest amplifier you could build is something like the gainclone. Search the board for gainclone or inverted gainclone.... You could build this circuits with any high power / high voltage / high current operational amplifier, the cheapest solution is ordering a sample at national or ti (opa549). If you want to learn more build a discrete amp and have a look at www.passdiy.com

8 Watt enough depends only on your speaker and how loud you expect to use them. I made an 1 Watt amp with SSM2211 chip (see pic) and with this little speaker connected on the pic its very silent. But if i use it on the big speakers (horns) it is absolute loud enough. One of the national or ti opamps will give you easy 50W or more if you need them and build a big enough powers supply.
 

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Bose(o) said:
Hello, I was wondering if you guys had any suggestions on an amplifier circuit that I can build for an upcoming computer speaker set that I will be building. TIA for any input!

P.S. I've read on this section of the forums and someone was raving about the sound from an eight-watt amplifier...eight watts? Wouldn't you need more? I'm asking these questions because the last thread that I posted did not receive any replies! Now, I'm getting close to building the speakers and would be forced to buy a plate-amp because I would be left out alone in the rain again. Yes, I am new to building amplifiers in general and need to start somewhere. Also, I have basic knowledge of circuits, have used ICs, resistors, caps (no transformers yet), and such with some breadboards but, am bored of making blinking LEDs and want some DIY audio!
I suppose you will not have your amp in the PC.
PC-speakers are mostly built into the speaker enclosure,
and Power Supplied by 12 VDC, via a cable from the Computer.

As the amp is outside the PC, there is not much advantage in
taking it from the low +12VDC in Computer.
I would suggest you take the power from the mains in the wall.

Then you can raise the voltage/power a bit, if you like.
And also don't get eventual Noise-disturbance from PCs Oscillators,
fans motors, and all that all that is housed in the PC.
--------------------------------------------------------------

What we are talking about now is a pair of Active Speakers
not only useable for PC. Any signal from other sources
can be connected to your speakers.
And you do not need to turn on the PC, for to get power.

You can now use Power IC amplifiers, suitable for dual/split supply.
Like +-12V or +-18V.
And you will find 10 times more different solutions ready for to apply.
If you restrict to single 12VDC PowerSU,
you will not find many interesting amplifiers.
At least not discussed here at diyAudio.
Hard to find any designs that bother to build good, HiFi amps
for 12 VDC.

/halo - likes active speakers, but not necessary for 12VDC. :cool:
 
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I have been using a boom-box/microsystem to listen to music and play games. Not much movies, just 2 channels is enough.

Now I need to move the system out into another room, so I'm building a little amp/speaker set for the computer.

I have settled on a circuit using TDA 2030, 4 amps bridged to form a 2 channel amp of about 35 W/ch. I found the ICs cheap, and had a transformer readily available, so that's why I settled on that circuit.

You can also look at the LM 3875/1875, the TDA 7294, etc. If you want to hotrod it, you could look at a biamped or triamped config, use Alephs/Zens. It can be as simple, or as complex as you like. The choices are the same as you will encounter - the computer is just another source, as halo points out.

One easy way is to get a kit from ESP or otherwise and throw together an amp. Since you do not have much experience that might be better than trying to do things from scratch. Also look at the Amp chip DIY forum, to get some more ideas, and search for gainclones on this forum.
 
Yes, sorry I didn't specify more into the usage.

I was definintly thinking about using the amplifier mounted in the sub like most 2.1 configs are that you can purchase from a source. I would just like to know now on what I have to decide on to build the amplifier. I took a look at National's chips and because I saw the LM4550 for 2.40 or 2.50 I thought I'd use those. If I use the gainclone circuit and substitute the LM4550 or any of the previously mentioned ICs what values will change?

I'm doing a lot of research on net and in books (Radioshack has a how to build Power supplies book that I'll buy), I'm not just mooching off of you guys.
Thanks a lot for your help.
 
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