Parallel xtra filter caps?

This video talks about similar capacitors //, which is OK, and often commendable.
What PFL200 seems worried about is the paralleling of a largish E-cap with a smallish cap, like 6.8nF in one example. This is completely counter-productive.
Some years ago, I made hundreds of systematic measurements of various combination using a VNA, and I posted a number of results on the forum (but due to the impaired search function of the new forum, I cannot locate them).

I could repost them, as I still have them stored somewhere, but the obvious conclusion was that 90% of the combinations produced unwanted dips and peaks in the resulting impedance, some of them very nasty. Around 5% were globally neutral, and 5% showed an improvement.
When the capacitance ratio is >100, the result is always detrimental.
1:20 to 1:50 is generally OK.
These are rules of thumb, valid for a direct paralleling, with negligible distance between the two caps, and no additional damping components.

The situation would be very different if the smaller cap is distant, at the remote end of an umbilical supply for instance.

Paralleling of similar caps is normally OK, and generally beneficial
 
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Someone correct me if I'm wrong, but aren't most discussions on Youtube of paralleling capacitors made by people who are talking about digital circuits (even if they are not specific about this) operating at high frequencies? They're discussing effects that occur in the tens of megahertz range, not 20kHz.
 
You'll have to fight that one out with Dave Jones, I think he wins the argument convincingly though, certainly not nonsense.
Oh, I see now.... You're showing me some youtube video of some guy named Jones..
Whom I never had any dealings with, nor do I know of his qualifications, background, schooling, and certificates/dimploma's.
Just some guy on a youtube video...... and I'm supposed to believe in what he preaches?
In my actual, real world Mr Tillotson, the "virtual" world doesn't supply me with the things I need to believe in, or food for my table.
Nor do I prefer to "argue" or fight with or concede to "virtual" beings.
 
I'm building an amplifier. Dual mono. Separate transformers (500VA, 8A) per channel, output stage supply voltage - 40V.
I want to organize the capacitors in the power supply as follows:
First (one channel) there are four 22000uF capacitors next to the transformer, then on the printed circuit board five centimeters from the output transistors there will be two low-impedance ones at 4700uF, and at the very collectors of the output transistors - 10uF per transistor (6 pieces in total - 60uF) - polypropylene .
Tell me, how successful will such a bunch be?
I will use capacitors in this order:

22000uF.jpg
4700uF.jpg
10uF.jpg
 
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Than why is there a parallel cap in the regulated power supplies of these signal meters?
Not in the 1604. It does look that way but the drawing is confusing.

A mica across an electrolytic did make sense in 1959. Electrolytic caps had large internal impedance, especially by 100kcs-1mc, and large dimensions so could not be right AT the connector or load. Modern e-caps have much lower stray impedance and can be mounted much closer to where they are needed.
 
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If by '1604' you mean the GM6014 than please look again in the schematic (see post #3). C504 (8 uF) is paralleled by C505 (100K = 0.1 uF). On the power supply circuit board they are also right next to each other.

Thanks for your possible/plausible explanation, which is in line with Elvee's explanation in post #7. C505 is not mica but polyester, but that probably won't matter much for your explanation.