"John Larkin" wrote in
message ...
On Wed, 17 Nov 2004 22:49:08 GMT, "Karl Uppiano"
wrote:

We're taking a flawed design, and adding band-aids on top of band-aids.
You
can make a perfectly good amplifier with one opamp and two push-pull
emitter
followers biased with a couple of diodes, similar to the first design
sketched in the OP's link. If that design draws too much idle current,
increase the emitter resistor. There's lots of stuff you can do to improve
that design without resorting to the demented design being proposed.


It's actually not a bad idea to have an opamp per output transistor,
if you do it right, which this guy clearly hasn't. I make a power amp
that uses 32 300-watt fets in the output (16 p-ch, 16 n-ch, +-200 volt
rails) and do just that. It forces essentially perfect current
sharing, nukes the device tc and part-part variations, and makes lots
of gate drive available.

John


I'm not saying it can't be done, but for the application at hand (a low
power amp running on a single supply) it seems simpler is better.