The power supply in my home build low profile HTPC has become very noisy.

It is a Zalman ZM500-GT 500W and very good until recently.

I want to replace it with a low noise job but do not want to spend more than I need to. Very few of those advertised on the Internet quote how many dbs to expect.

Does anyone have any knowledge of what might be a good choice?

TIA
--
Mint 20.04, kernel 5.4.0-42-generic, Cinnamon 4.6.7
running on an AMD Phenom II X4 Black edition processor with 8GB of DRAM.