Comparator question.

[Kipper4]

I think I tried this before using a common or garden TLxxx series and it didn't end well as I remember.

So what's a good op amp to make a comparator with?
Is it ultimately cheaper to buy a dedicated dip 8 chip? If so which?
I found the LM393 on CPC

http://cpc.farnell.com/texas-instruments/lm393p/ic-comparator-dual-dip8-393/dp/SC10206?CMP=KNC-GUK-CPC-GEN-KWL-TEXAS_INSTRUMENTS&mckv=sK2CcpM7u_dt%7Cpcrid%7C189938957945%7Ckword%7C%7Cmatch%7Cb%7Cplid%7C&gclid=CLvQjfi3u9MCFcHGGwodcqcOGQ

Is this a suitable chip for audio applications.

I'm not even sure what I intend to do with it yet as a final product.
But I am sure I want to input 2 signals and have the stronger of the two dominate the output.

Or am I totally barking up the wrong tree.

School me please.

[anotherjim]

The LM358 doesn't seem to mind working as a comparator. Really, you want an op-amp like the 358 that can switch output to ground.

The LM393 is a fine comparator, but the output is different from the op-amps. When +in > -in, the output is a transistor collector switched on to ground the output. When -in > +in, the output transistor is off. So it is inverted output compared to an op-amp AND needs a pull up resistor on the output to a +supply or it will never go high.

There is also the LM392, an 8pin that contains one of the 358 amps and one of the 393 comparators, which could be space savingly useful - must remember to order some sometime.

[PRR]

> am I totally barking up the wrong tree.

Remember a tree has roots. And signal sings above and below ground. When it swings low, which signal do you want??

The other thing is, a 0.01V signal makes a 10V (or 4.5V) output. All subtlety is lost.

[anotherjim]

But I am sure I want to input 2 signals and have the stronger of the two dominate the output.

If thinking here is that one of 2 envelope detectors feed each input, the output will be high or low depending which is more positive at any time. Comparator output is digital. Care would be needed to stop it toggling the changeover on ripple.

[antonis]

But I am sure I want to input 2 signals and have the stronger of the two dominate the output.

Comparator output is digital. Care would be needed to stop it toggling the changeover on ripple.

A relatively big resistor on POSITIVE feedback loop should set hysteresis threashold... 
(it's value can be calculated according to comparator's High output - if it's an open collector kind then it should be only considered to Low state, in absence of any "pull-up" resistor..)