[tortugaranger]

And here we have an example of what happens when you power the V2.1 board (with stock auto-cal op amp) with 20 volts when 12 volts is spec and the op amp is rated for max 16 volts. Quite a spectacular fail. Visual fireworks, snap-crackle-pop and no doubt a fair amount of stink. I'm not naming names. 

If you want to run the V2.1 board with up to 30 VDC you'll want to opt for one of these:  http://www.tortugaaudio.com/product/ldr3x-auto-cal-high-precision-op-amp-upgrade/

[jtwrace]

Stunning.  Nice job!   

[TJHUB]

You know you're not supposed to let the magic smoke out of stuff like that.   

If you want to blow stuff up, that was a VERY good job.   

[gregfisk]

Someone was playing Tiny Tim's "tip toe thru the tulips" and that op-amp op- ted out.

[glynnw]

Just be warned - because a wall wart sez it's 15V don't mean it really is.

[tortugaranger]

Just be warned - because a wall wart sez it's 15V don't mean it really is.

I recently evaluated 2 alternative wall-wart style power supplies. Both are linear "12" volt units but one is unregulated and the other regulated. Of course the regulated PS dished out 12 volts. The unregulated put out almost 18+ volts and that was with AC main at exactly 110 VAC from a variac supply. It was over 20 volts with AC main at 125 VAC.  Yet both are 12 volt nameplate. If I didn't know the unregulated was indeed unregulated you couldn't tell by the nameplate info. Had I unwittingly plugged the unregulated into a stock V2.1 board, it would have been op amp toasting redeux.