"Chris Morriss" wrote in message


An LM3875 makes a useful little amp. It's basically a power op-amp
with just the five active pins, so it's easy to wire up a neat design.

I've got a three channel LM3875 amp I built to try out active
crossover networks to drive the bass, middle and tweeter of speakers.
I've used stabilised +/- 35V rails and it sounds and measures pretty
well.
(Actually, the wiring structure is important, I've heard of marginally
stable 3875 amps where people don't know how to return signals to the
0v line in the right place.)

The latest version of this part appears to be the LM4780 - reference
http://www.national.com/ds/LM/LM4780.pdf


http://www.national.com/whatsnew/ind...=779&v=c&p=120 shows a number
of forms of the LM3875 device listed as being "Obsolete".