colin wrote:

"Winfield Hill" wrote in message
Eeyore wrote...

In response to various posts please find attached a mic amp
which has seen volume production in commercial equipment.

Feel free to ask any questions / criticise whatever.

It's nice to see the diff-pair currents going directly to
the output opamp, with it's 6.8k resistors. But why'd ya
steal away loop gain so aggressively by choosing 680-ohms?

Now theres no resistors, the diff voltage input to the op amp is always
zero,

Damn small at least !

so theres no diff voltage accross the 680r so they dont have an effect on
diff voltage.

You got it.

Graham