Hi Dave, i think you'll have a very difficult if not impossible job finding Schottky diodes rated high enough (voltage wise) to replace the HT supply diodes
Really. I'm sure I ordered the ones that WAD recommended. Perhaps they're not Schottkies and just some other type of ultra fast diodes. I'll check my RS order and let you know what I've got......
Source: Apple TV 4K - DAC: Beresford Bushmaster Mk II - Preamp: CI AudioPLC-1 Mk II - Power Amps: Musical Fidelity 550K mono blocks - Speakers: Wharfedale Opus 3 - Cables: Mark Grant etc - Misc: Belkin PF30 mains filters.