Burn-in seems to be a case of burning in the ears. That said, my power amp (Odyssey) is said to absolutely require burn-in, even by the manufacturer (Klauss, who is well respected throughout the audio community from what I can tell, unlike others). Of course I bought mine used, so I cannot attest one way or the other. In general, I still feel that claims of many hours of burn-in required are absolute bullshit. Particularly the B-I blogs on HF...