Amp opinion

Thread Starter

silent_light

Joined Nov 6, 2008
8
Here is a 4W audio amplifier from www.discovercircuits.com that is powered by 8 to 12 volts. If you intend to handle stereo you will need to consider building two such amplifiers.

If you are thinking of using a standard 9V transistor battery, you are going to have difficulty getting any useful life from the batteries.

hgmjr
What do you think about this amplifier,is it worth ?
What will you choose ,TDA 2003 (3W 4Ohm before clipping) or this 4W AF amplifier ?
 

jj_alukkas

Joined Jan 8, 2009
753
First of all, decide if you seriously need to run them on batteries. An 8ohm speaker raises your power requirement but if you like to stick to those, its fine.

Using a 3W amplifier is good for your speakers and batteries. 4W amps tends to distort at the higher volumes with a 4w speaker.

And you wont end up with a small amplifier as all amps above 2w require fairly a large heatsink.. So either you have to use a metal cabinet ( with insulator pads) or a larger volume to fit the amp. Amps with TDA2003 are good for your option if you intend to build one. TDA2005 is more powerful but is not reccomended. If you are getting it as a kit, try TBA810 x2.. It provides great quality audio, lower heatsink requirements and max power of 7w(which can be limited) but a bit complex circuitry which is the reason for its audio quality. The disadvantage is that it requires a larger board area but it runs good at 9 & 12v
 

Audioguru

Joined Dec 20, 2007
11,248
The "4W" amplifier has an output of 5.4W into 3 ohms when its power supply is 13.8V.
With a brand new 9V battery its output is only 0.68W into 8 ohms. When the battery voltage drops to 6V then the output into 8 ohms is only 0.2W.

With a brand new 9V battery the output of an TDA2003 into 8 ohms is also only 0.68W.
When the battery drops to 6V then the amplifier won't work.

A TDA2005 is a bridged amplifier IC. With a brand new 9V battery its output into 8 ohms is about 2W. With a 14.4V supply its output into 3.2 ohms is 17.6W. it won't work when the battery drops below 8V which will occur quickly.
 

millwood

Joined Dec 31, 1969
0
it is pretty good.

But if it is your first amp, I would go with a tda2003/2030a/lm1875. it is a lot easier to get those ic amps running than to get a discrete amp running.

a discrete amp has advantages in high powered applications.
 
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