[sdiy] 1N914 vs. 1N4148 ?

[The Peasant]

> Has anyone seen people using fast recovery diodes in
> 60Hz power supplies ??? What's up with that ???
> 
> Is it some audiophile thing ???

Yes.

When the ac cycle reverses the bias on a silicon diode, it tends to ring at 
high frequencies. (This ringing can be seen on a good oscilloscope.) This high 
frequency ringing can end up modulating the power supply and/or the audio 
signal, and can make quite a difference in sound on a good stereo system. Fast 
recovery diodes do not exhibit this problem nearly so much, and so using them 
will minimise this source of "noise". However, I have found that using a 
snubber network across each rectifier diode of a standard silicon bridge will 
also cure this problem, I use 0.01uF in series with a 100R resistor for this. 
And this solution is a lot cheaper than using those expensive fast recovery 
types.

Take care,
Doug
______________________
The Electronic Peasant

www.electronicpeasant.com