totem pole main filter caps Fender Blackface

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martin manning
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Re: totem pole main filter caps Fender Blackface

Post by martin manning »

Thanks for the explanation. I assume one could reduce the power rating of the balance resistors, if the maximum applied voltage is lower than the capacitor rated voltage.

Some common examples (almost universally copied), are 220u 300V caps with 220k or 270k balance resistors for the HV reservoir, and 47u 300V caps with 470k balance resistors for preamp filters. Those values seem to work, since I haven't heard of any power supplies burning up due to leaky caps. The Nichicon calc gives 139k and 301k respectively, roughly half to two-thirds of the common practice.
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