[sdiy] 1N914 vs. 1N4148 ?

[Roy J. Tellason]

On Thursday 29 September 2005 12:43 pm, The Peasant wrote:
> > 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

I remember seeing some stuff that had small (1nf?) ceramic caps across each 
diode,  and always wondered what these were in there for...


-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"