I complete agree but it is not certain that all products with fans will engage them during use.
I have read many reports from owners that claim they never turn on.
It's different with amplifier transformers. These amps have had audible hum from my listening position: Sunfire Cinema Grand, Outlaw 7500, ATI AT3005, Parasound A21/31/51, and ATI AT6002's. The Parasound were much better than the others.
I had an ATI AT6006 with custom wound transformers that has almost no hum most of the time but was sensitive to DC from a cabinet fan. This would oscillate with a 30 second period. Again, there are mixed reports from owners. Unit to unit variance and power quality are factors.
I found the answer, stop buying amps with transformers or fans. It's militantly stupid person proof
- Rich