Power Supply - Bypass Capacitors?

Loud & Clear

Loud & Clear

"Welcome To The Machine"
Is there a general ratio for using bypass caps on big power supply caps? I need to bypass a couple 10000uf capacitors. I know that you can even bypass the bypass capacitor, if it is rather large... This is a New one on me... Thanks for the help guy's... :scratch2:
 
Register to hide this ad
The standard decoupling/bypass cap is a .10 mfd film that has excellent high frequency characteristics.
 
d3imlay said:
The standard decoupling/bypass cap is a .10 mfd film that has excellent high frequency characteristics.
Click to expand...
Ok, Thanks d3imlay... I've grown fond of the 1% dayton metalized polypropylene. Perhaps this may be a job for the polypropylene film & foil. :scratch2:
 
I keep a supply of 2.2µf 250V metallized polyester caps around for supply cap bypassing.
 
I put them in when I build to assuage the audio paranoia elf that often sits on my shoulder whispering.

However I've never heard a demo, my own or another's, that convinced me they were doing anything audible.
 
I've read several articles that advocate the use of bypass caps. I'd read the article and think, "ok, that makes sense"....then I'd read articles that disputed the need for bypass caps and also think, "gee that makes sense too"....

So I've come to the same conclusion as soundmotor. Usually I put them in, but I'm not sure they do anything.
 
Well, when guys like John Curl and Nelson Pass use them, and so do many other designers and manufacturers (Sansui, for instance, used bypass caps on all their top gear), then who am I to second-guess them? I just do it.
 
EchoWars said:
Well, when guys like John Curl and Nelson Pass use them, and so do many other designers and manufacturers (Sansui, for instance, used bypass caps on all their top gear), then who am I to second-guess them? I just do it.
Click to expand...
I've seen what you've seen Glenn. I will go ahead, and bypass the buggers... :)
 

Attachments

  • Example P.S. Capacitor Bypassing.jpg
    Example P.S. Capacitor Bypassing.jpg
    174.3 KB · Views: 388
The PS rail circuit can be seen as the "back door" return loop of the signal circuit path. Yes, it matters, do it. Using caps as good as the best signal path caps in the unit isn't overkill.
S.B.
 
A look at most digital circuits will reveal a .10mf cap across the power supply pins. Even though the actual current is small, the rate of change (DI/DT) is huge. The caps prevent oscillations etc. Although ceramic caps are often spurned in the audio industry, especially for coupling, they have good high frequency characteristics and are cost effective for many decoupling circuits.
 
I have bypassed some of my power supplies with 2.2uF PIO bypassed with 0.1uF Teflon.

And by the way, the old rule of thumb was bypass a 1000uF with a 100uF bypassed with a 10uF... it gets awful!
 
"Supposedly" you are imparting a little of the flavor of each "better" capacitor on your power supply.

So bypass a stock electrolytic with a very low ESR electrolytic, then PIO the PP then Teflon. When you run out of smaller and better sounding caps, stop!

Anyway, decades ago that was the thought.
 
You must log in or register to reply here.
Back
Top Bottom