[sdiy] 1N914 vs. 1N4148 ?

[KA4HJH]

>> 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.

The only problem with this approach is that disc caps are notorious for
buzzing. I suppose you could go through a pile and find the ones that are
less noisy. What caps do you use for this?

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"