i went thru that recently .7 pounds of noise soon as it was switched on .
couldnt hear .big bummer .it was a 100 amp switching supply.had to sell it.
This thread is about Iotas.The 100 amp supply you had,was it made by Iota? My Kenwood 440 is powered from one of my Iotas,no noise.Maybe the Iota is filtered better? Do all switching supplies generate noise? Does anybody know?