I did something truly nuts tonight, listened to the BHSE at max volume (from a 2V source) just to see what would happen. What I listened to was the beginning drum solo of Megadeth - Trust with the SR-007 Mk1. It was more then enough to make the Omegas start to vibrate but both headphones and amp held up perfectly. Now we are pretty far away from the imminent destruction territory for the Pro bias sets here (+/-600V rails would land us there) but still this was very loud indeed.