Hello!
I am trying to figure out what DC voltage I should be rating a 0.1uF C0G/NP0 for a hum block circuit like the Valve Wizard has put in his amp grounding pdf (page 15). The capacitor is between the circuit ground and chassis ground. It isn't that easy to find out what DC voltage rating you should be using for AC signals - Kemet has a pretty good page on how it suggests you approach AC voltage on their DC rated ceramic caps.
I'm not really sure what the appropriate voltage rating for a capacitor in a hum block network would in be in, say, a power amp with 30V +/- or even 100V +/-. I'm imagining that most of the signal current present would return to the transformer windings, leading to a limited voltage difference across the terminals of that cap in the hum block, but maybe my mental model is wrong. If I am wrong, then Kemet's document would be suggesting some pretty high voltage ratings for the cap, in which case I would turn to polypropylene film caps.
Thanks for any advice.
I am trying to figure out what DC voltage I should be rating a 0.1uF C0G/NP0 for a hum block circuit like the Valve Wizard has put in his amp grounding pdf (page 15). The capacitor is between the circuit ground and chassis ground. It isn't that easy to find out what DC voltage rating you should be using for AC signals - Kemet has a pretty good page on how it suggests you approach AC voltage on their DC rated ceramic caps.
I'm not really sure what the appropriate voltage rating for a capacitor in a hum block network would in be in, say, a power amp with 30V +/- or even 100V +/-. I'm imagining that most of the signal current present would return to the transformer windings, leading to a limited voltage difference across the terminals of that cap in the hum block, but maybe my mental model is wrong. If I am wrong, then Kemet's document would be suggesting some pretty high voltage ratings for the cap, in which case I would turn to polypropylene film caps.
Thanks for any advice.
