Caps across the diode in #183

[grtamp]

In the #183 schematic; are essential the 0.01uF capacitors across rectifier diodes or you can do it without?
Thanks

[glasman]

The .01uf are an old school trick to reduce switching noise that was common on early day diodes. Probably not really needed thes days if you are using decent parts. I prefer UF4007 for that position.

Back in the old days the practice was to put a 470K and .01uf in parallel with the diode in the string to reduce the noise and equalize the voltage across them.

[martin manning]

Not everybody likes fast diodes though...

http://www.passlabs.com/pdfs/articles/powersupply.pdf

"Yeah, sure, rectifiers are important, after all, the AC has to get converted to DC, but I don't like the fast recovery types that some audiophiles have raved about. Fast recovery means that they withstand many amps and volts in a tenth of a few nano-seconds, something we don't see very often on the old 60 Hz AC line. They are essential element in switching power supplies, but for regular "linear" power supplies, I much prefer SLOW diodes, and we create them by placing small capacitor circuits across the diodes, which greatly reduces radiated noise."

[grtamp]

Thanks for your explanation glasman!!