GGG Mini Mixer blowing IC

[dylar]

Hi (relative noob here)-
I built the GGG Mini Mixer - twice in fact - and I have had the same error both times.  I have checked it numerous times and the soldering is fine and there is no short on the board that I can see.
http://www.generalguitargadgets.com/diagrams/mixer_lo.gif
Here's what happens: The LED blinks in time with a loud static blip - it happens regularly like the tick of a clock, at about a 1/2 second interval.  This happens for around a minute and then the TL072 heats up and blows. 
The only thing I have done differently from the schematic is to wire the power supply to a 9-volt wall wart instead of a battery.  It is part of a daisy chain that is made specifically for powering stompboxes, so I know the voltage / amps are fine.  I guess there is a possibility that I reversed the polarity on the power supply...
Any ideas on why the TL072 would function like this?

[euronymous0001]

Here's what happens: The LED blinks in time with a loud static blip - it happens regularly like the tick of a clock, at about a 1/2 second interval.  This happens for around a minute and then the TL072 heats up and blows. 
The only thing I have done differently from the schematic is to wire the power supply to a 9-volt wall wart instead of a battery. 

positive should go to the pad atop R12, then the negative of your PSU should go ground

are you sure that your PSU is DC and not AC

[dylar]

Wow, I am an idiot.
I had not cut into a wall wart like this before, and I had indeed reversed the polarity...red wire was ground and black was hot.  That seems counter-intuitive.  Suppose I should have tested instead of guessing.

[R.G.]

...That seems counter-intuitive.  Suppose I should have tested instead of guessing.

Yep - Mother Nature does not have human-type intuition.