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previous: John Stokes Guys, I've seen claims in the audio... -- 11/3/1999 10:29 PM	View Thread

Re: Rectifier diode recovery time

11/4/1999 4:22 PM
Dai Hirokawa	Re: Rectifier diode recovery time >>I've seen claims in the audiophool rags that fast recovery diodes make an audible difference over standard recovery diodes when used as power supply rectifiers Hi Stokes, I tried fast-recovery diodes for the B+ supply in a Marshall a while back, and my impression (as I recall) was that the transients were too fast and kind of hurting to my ears(maybe using fast-recov. and a series resistance is better? perhaps?--haven't tried that). Also, I've tried a tube rectifier(would these count as "slow-recovery"?) for the C- supply(totally impractical experiment), and the sound seemed worse, so maybe fast-recovery diodes have potential here? Also, I've tried the technique of bypassing each diode for the B+ rect. w/2n2 or .01uF ceramics. My understanding was that this would reduce switching noise. As for the sonic benefits--they seem to be pretty subtle. I removed some bypasses when I suspected they were causing some probs.(turned out they weren't) and (I wasn't expecting any change in sound--I was starting to think they really didn't do anything after having them on for a couple of years) I noticed a very subtle change in sound for the worse. Also, I've heard of some Hi-Fi manufact. enclosing diodes in a metal tube(and shielding them, I presume)to keep them from radiating noise into the circuit. Anybody have experience w/that? >Guys, I've seen claims in the audiophool rags >Just another ploy to use hype to justify jacking up the price? I personally find (probably too much) emphasis is placed on products that give a disproportionately small "improvement"(or change) in sound for the prices charged. Dai Hirokawa

11/4/1999 4:22 PM

Dai Hirokawa
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Re: Rectifier diode recovery time

>>I've seen claims in the audiophool rags that fast recovery diodes make an audible difference over standard recovery diodes when used as power supply rectifiers

Hi Stokes,
I tried fast-recovery diodes for the B+ supply in a Marshall a while back, and my impression (as I recall) was that the transients were too fast and kind of hurting to my ears(maybe using fast-recov. and a series resistance is better? perhaps?--haven't tried that). Also, I've tried a tube rectifier(would these count as "slow-recovery"?) for the C- supply(totally impractical experiment), and the sound seemed worse, so maybe fast-recovery diodes have potential here?

Also, I've tried the technique of bypassing each diode for the B+ rect. w/2n2 or .01uF ceramics. My understanding was that this would reduce switching noise. As for the sonic benefits--they seem to be pretty subtle. I removed some bypasses when I suspected they were causing some probs.(turned out they weren't) and (I wasn't expecting any change in sound--I was starting to think they really didn't do anything after having them on for a couple of years) I noticed a very subtle change in sound for the worse.

Also, I've heard of some Hi-Fi manufact. enclosing diodes in a metal tube(and shielding them, I presume)to keep them from radiating noise into the circuit. Anybody have experience w/that?

>Guys, I've seen claims in the audiophool rags

>Just another ploy to use hype to justify jacking up the price?

I personally find (probably too much) emphasis is placed on products that give a disproportionately small "improvement"(or change) in sound for the prices charged.

Dai Hirokawa

Replies:

Rob W. Re: Rectifier diodes / Tone Changes -- 11/4/1999 5:17 PM