does diff. Volt matter much in Film cap?
- Thread starter knappster
- Start date
Nostradoomus
Well-known member
that's what she said
The only practical issues I can think of are:
For electrolytics, ESR could increase with a much larger cap
For some ceramics, their actual capacitance can drift out of tolerance if used far outside of the designed voltage range.
For poly/film, the only thing I can think of is *maybe* wider tolerances on much larger caps.
Now, if it's leads are bent and it's free-floating, you could have issues with continuity down the road if the solder joint fails. Bouncing around on a pedal board and whatnot.
Are you in the states? I could mail you a greenie or box in a PWE Monday. If needed, just PM me
Last edited:
darwin999
Well-known member
Clearly the rated voltage of the cap needs to exceed the actual max voltage it will face in the circuit. This ensures that its capacitance is nominally constant, and its lifetime is not degraded (i.e., it won't get damaged). It's best that the rating exceeds the actual voltage by a good margin (say ~50-100%), for best performance. And it's always wise to read the spec sheet of any electrical part, for more details and to educate yourself.
If a quality capacitor is being used within it's rated specs, then it should sound fine - i.e., like an ideal capacitor. Here, 'quality' includes things like small variation in value, low ESR, low variation with voltage, etc.
If a quality capacitor is being used within it's rated specs, then it should sound fine - i.e., like an ideal capacitor. Here, 'quality' includes things like small variation in value, low ESR, low variation with voltage, etc.
One potential problem with overly-large capacitors is that they can act like an antenna and pick up RF/EMF noise. Assuming your circuit is going in an aluminum enclosure, you have some implicit protection. And if you're building something designed to distort (e.g. overdrive/fuzz), absolutely perfect signal integrity isn't really necessary.
I've used plenty of oversized caps in my builds, and never experienced RF noise. But when I hung out at diyAudio, the risk of big (physically) film caps acting as antennas was oft-repeated. Hence, I think this is more of a concern in hifi circuits, when you're going for noise measurements far below the range of human hearing.
I've used plenty of oversized caps in my builds, and never experienced RF noise. But when I hung out at diyAudio, the risk of big (physically) film caps acting as antennas was oft-repeated. Hence, I think this is more of a concern in hifi circuits, when you're going for noise measurements far below the range of human hearing.
