I upgraded the transformer only to 24v... my chime is still 16v, and is running beautifully. I bought the transformer from Amazon
I opted to go with the more expensive brand name (Honeywell) than the other off brands...after going thru multiple transformers and chimes, I figured go with a name that I trust... (Honeywell thermostats here too as well.)
Same experience here. I had been struggling with finding a way to suppress the buzzing noise. I added the resistor that came with the Hikvision
doorbell and it did kill the buzzing. However, most of the time when someone rang my doorbell, the chime would not ring or only ring very softly with a "ding", but never the "ding" followed by "dong". Very frustrating. I removed the resistor and used the 24VAC taps on this transformer
Hampton Bay Wired Door Bell Tri-Volt Transformer Compatible with All Video Door Bells-HB-125-03 - The Home Depot.
Earlier comments on this thread from
@skylab001 and
@tangent were right on the money to understand what is going on and why the 24V transform helps. Electrical power is Volts * Amps. By bumping the voltage up from 16 to 24, the amps drawn by the Hikvision doorbell drop proportionally. The solenoid in the chime is fundamentally a electromagnet driven by current. So voltage up, current down, and less vibration of the solenoid plunger which means less noise.
In my case, there is still a very slight humming of the chime after changing to 24V. By tweaking the two screws holding the chime to the wall to minimize the very slight buzzing sound to the drywall, the only hum I can hear is if I have my ear almost touching the mechanical chime. And, almost as important, the doorbell chime now rings "ding" "dong" everytime the doorbell button is pushed.