Just had my Levinson 23.5 serviced by an authorized Levinson repair center with many years of experience, capacitors were replaced not the big blue capacitors the medium smaller ones on the board 680UF 100V and other small transistors and resistors, there is no hum from the speakers at all, dead silent but when I opened the cover to look at the repair I place my ears on top of the amplifier I hear a slight hum you have to get really close to hear it. I assume it is normal maybe one day when I can afford a new amplifier I will have something to compare but I am happy with the Levinson 23.5 don't have any desire to replace except for a Levinson 33H.
