Need help troubleshooting Attack/Release circuit!

[elskardio]

Turns out R72 and R40 were interchanged due to an error on the pcb silkscreen  :-[

I'll try to run some test today!

Thanks again for you help!

 

[PRR]

> R72 and R40 were interchanged

That does not explain Q3 smoking.

 

[JohnRoberts]

I would be looking for a similar mistake on both current mirrors. The heat and smoke released was because "both" were turned on too hard. If just one was turned on too hard the other would not overheat. While it might put a hurt on the open collector comparator.

The voltages around the bottom current mirror suggest that Q3 is turned on pretty hard too. 

This is also why the +/-15v rail could not keep up.

JR