2 stage differential amplifier

:?: i have seen a circuit design of a 2 stage differential amplifier using split supply of +/-15v. however it does not say whether this circuit can be employed on an audio power amp. here's my following questions.
1. has anybody have used this circuit
2. can it be used in audio power amps?
3. does it have a distinct advantage over a single diff. amp?

p.s. the circuit employs on the 1st stage fet transistor and the 2nd stage bipolars.

thanx

Two stage diff amps have been around forever, so there are countless versions of them. You'll have to post the schematic if you expect to get an intelligent answer.