Quick question about using low leakage / low noise e-caps like the old orange Elnas and current Nichicon KLs, I understand the benefit of using them for coupling but unsure if there’s any upside in using them for decoupling to ground, or downsides. These days the cost is a few pennies difference between LL, audio, or general purpose caps so basically I’m wondering if there are negatives, or it makes no difference. Nichicon doesn’t publish complete specs so I’ve no idea if there were trade offs to achieving low leakage like lousy ESR, resistance, or ripple values, not that high ripple is that important for coupling/decoupling. I know it would be preferable use a film cap but that is not a consideration here, I'm just curious when using low leakage e-caps for decoupling to ground, for example in a phono stage, do you get the added low noise benefit or you can actually make things worse?
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A voltage regulator is better than any electrolytic capacitor. 😉
With a regulated supply, the decoupling capacitors need only remove high frequencies. The capacitor values are in a range where tantalum works well.
Ed
With a regulated supply, the decoupling capacitors need only remove high frequencies. The capacitor values are in a range where tantalum works well.
Ed
Yes, there is usually a regulator on the B+ going to the preamp stages. I'm just curious if low leakage KL type caps can be used as general purpose caps with no downside. Looking at Japanese hifi from the '70s they were use sparingly, I assume because of cost, today there hardly any cost difference, so if there is no downside to using KLs I would just stock up on KLs for both coupling and decoupling.
From a few measurements I've made of 'lytics, lower leakage is correlated with higher ESR. The very lowest ESR caps (polymers) have by far the highest leakage.
The standard method of getting more bang for buck in decoupling is to use a capacitance multiplier
https://www.electronics-notes.com/a...transistor/capacitance-multiplier-circuit.php
You can also use two or one opamp too in a similar circuit. But the single transistor one is pretty good. The capacitance is multiplied by the transistor gain. So if that is (typically) 200, a 10uF capacitor can be made to look like a 2,000uF capacitor.
To get + and - rails you use npn for one and pnp for the other.
https://www.electronics-notes.com/a...transistor/capacitance-multiplier-circuit.php
You can also use two or one opamp too in a similar circuit. But the single transistor one is pretty good. The capacitance is multiplied by the transistor gain. So if that is (typically) 200, a 10uF capacitor can be made to look like a 2,000uF capacitor.
To get + and - rails you use npn for one and pnp for the other.