Low-voltage chipamp newb stuff

[Bear]

I've got some 386's on hand to breadboard some beginner poweramp stuff with, but I get that they're limited beyond their available power output.  The appeal of low voltage components for experimenting is high, though--a 9v is easier than doing a bipolar supply off AC mains.

So I'm looking for other components worth experimenting with.  The LM380 is supposed to be the non-crippled parent version of the LM386, and it looks like it could run quite capably off a wall wart with decent current capacity, simplifying life greatly.  Or am I off base on that?  Is the heatsinking via the pins in the 14 DIP as easy as advertised?

Any other low power chip amps of note that I could similarly outsource the power supply to batteries or wall warts or such?  Any decent "cookbook" references for any of them?

[J M Fahey]

There´s a lot of more modern chips, around 1W and powered by 9V .

Just yesterday I went downtown to buy a few TDA2822 , the modern "2 improved LM386 in a chip" version.

On first sight it "looks"  more complex ... until we realize there is 2 of them inside 1 chip
And it works down to 3 V !!!
http://www.circuitstoday.com/tda2822-amplifier-circuit

For a wider discussion on options:
http://theradioboard.com/rb/viewtopic.php?t=4447

[Bear]

Thanks, Juan!  I have been following those links and beyond.  The tda2822 is interesting--can't believe I'd never seen that one before.

Reading up on mixed-mode feedback, something I wanted to play with, I've gathered that fixed gain power opamps don't work ideally for that circuit type.  But I can't find an explanation of why.  Any explanation or reading anyone can point me to?

Thanks!

[J M Fahey]

That one is easy
On regular "power Op Amps" which is what they are basically, we choose the NFB net we want, usually voltage  NFB which yields constant voltage which means low impedance, but we also can choose current feedback which is the opposite , or someway in the middle, mixed feedback.

But fixed gain chips do so by already having internal NFB, which because of versatility is voltage type.

And we have no access to it.

In fact, oldstyle LM386 and TDA2003 do have 1 leg connected to 1 node of internal NFB , so we can tweak it a little.