LM 383 help

[hobbyguy]

Originally Posted by gootee

There's this new thing they have, called "Google.com". You can type things in, there, and it searches the internet for them and then gives you links to click on to see what's at each of the resulting web pages.

The only thing that ruins it and makes it almost totally useless is that then you have to actually READ to find out what you wanted to know. (It's almost as ridiculous as thinking about actually pulling a bookshelf speaker off of the shelf to look on the back to see how many Ohms the impedance rating is, or looking up the specs on the internet.)


HINT: For less than the price of a nine-volt battery, you could go to a few garage sales and buy four or five used "wall-wart" DC power supplies. If you can find a couple of 12V-15V ones that can put out a couple of amperes each, you could power some more-interesting chipamps. And I'm sure that you could find some 9-volt ones. You can usually connect the positive of one and the negative of another one to make a ground and then you have both + and - voltages from the two remaining wires.

No sir I did not know of this thing you call google...
I did, that's where I got this schematic, why do you thing I'm here, just wanted to know from a pro on audio or on the amp.

Originally Posted by sofaspud

Ahhh... one more opportunity to slip in another sofaspud platitude.
People who don't make mistakes don't make anything at all.
hobbyguy, is that a Fairchild part you have there? I have the datasheet for the TDA2002.
The circuit you show is the single-supply version. gootee is correct that 18V is the max operating voltage, but mostly wrong in making a federal case out of speaker impedance. I'd bet my paycheck that your bookshelf speakers are 4 to 16 ohms and therefore of little to no consequence in the grand scheme. madtecchy is mostly correct in that a 9V battery will not cut it as a power source for your amp. Surely you have a 12VDC wall wart around your place? That's what I suggest you use, at least at this stage of testing/troubleshooting.
And salesmen generally aren't known for being pillars of integrity when they want to make the sale. I'm ignoring all that "they said" stuff.
Anyway, let's compare what we have now to work with and go from there.
Here's the typical app circuit from the datasheet:

well thank you sofaspud

Originally Posted by sofaspud

Looked over both schematics above and everything seems to check out. Yours doesn't include the output zobel network (C5 & R3 in the datasheet circuit), but I wouldn't think it is a necessity at this point. Probably a good idea to include it though if you have the parts handy. I also see you have a gain of 100. That might be a bit much, depending on your signal source - you can decrease the gain by increasing the 2.2 ohm resistor to 4.7. That makes the gain 47, which should easily allow an input of something like 100mV or more.
BTW, ignore the dashed-line components for now. They just tweak the frequency response.

Yeah I was searching again for the TDA2002 and I got more schematic that you provide it, and thank you again sofaspud.