I have a Ref5 SE that has the same polycarbonate cover. It is sitting on top of my rack with the ultimate ventilation. The cover is STILL WARPED! It has nothing to do with adequate ventilation. Lostbears nailed it, it's the 6550 power tube. Flipped it over and in 5 minutes it bowed again. I am ordering a metal cover to replace the plastic POS!
ARC Reference 10 melting polycarbonate cover
Any similar experience? The 6550c tubes are melting the poly cover in the first 7 hours of usage...