Buzzing noise started on my Breville Oracle BES980XL. As per various YouTube videos, I located the solenoid valve in question and cleaned it, which lasted a few months. Finally it began again and cleaning it didn't do the trick.
I found the part on Coffee Addicts and it worked perfectly. One caveat I may add is that the part does not come with the replacement gaskets, perhaps advising to keep the old ones would be a good heads up for potential buyers. I kept mine and they worked with the valve perfectly. Back to great coffee extractions and no buzzing whatsoever.
Shipping was fast and easy (Despite minor delay from major spring snow storm out west).