From Bryston's website:
"Each and every Bryston amplifier undergoes a very extensive "burn-in" procedure. Following a complete operational checkout, every amplifier is placed on a test-bench and run for 100 hours at full output (one hour on/ one hour off for additional thermal stress), with a high frequency square-wave input and a capacitive load. This extremely rigorous burn in quickly "matures" components and weeds out any potential premature failures. The result is reliable trouble-free performance for many years, and is backed by Bryston's exclusive 20-year full warranty."