Genome wrote:

"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.


Here you go...... Listening to the criticism that others are giving you I'd
do something like this. As to wether I've got it right is another matter.

I'd also claim that U1 and U2 also cascode the input stage improving
bandwidth.

That's an interesting design.

The constant current source in the 'tail' I've seen before. ISTR one guy I know
who did that found it increased the noise unfortunately. You're missing the
variable gain bit though. You need 2 current sources in place of Q5 with the
gain setting bits connected between Q1 and Q2 emitters.

The 'collector loads' are cute too. I'm tempted to try it btw but I'm just about
to post another one that's a bit more up to date. Check that one out.

Graham