Replacing some old SKE 1/04 diodes for newer and quieter ones
The SKS-01/04 is only rated for 3500 uF while the SKE-02/04 is rated for 5000 uF which is shown to be used.
The diodes might be hot but the caps make it noisy. Use good ones.  You might want to replace all the large e-Caps with better ones.