Author Topic: Bypass caps....why use them?  (Read 723 times)

Offline mresseguie

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Bypass caps....why use them?
« on: September 23, 2017, 09:44:29 PM »
In addition to the thread that Charles began, I've read in other forums where people have added bypass caps to crossovers to improve sound.

What are the rules/guidelines for using them?
Do all crossovers benefit from their addition?
Can they be used in DACs? In amps?

Michael
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Offline steve

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Re: Bypass caps....why use them?
« Reply #1 on: November 26, 2017, 09:46:20 PM »
In addition to the thread that Charles began, I've read in other forums where people have added bypass caps to crossovers to improve sound.

What are the rules/guidelines for using them?
Do all crossovers benefit from their addition?
Can they be used in DACs? In amps?

Michael

It used to be that I could find "perfect" capacitors for very reasonable prices, which did not need bypassing. Those days are long gone thanks to "capacitor comparisons" by amateurs, that were not only worthless, but actually caused the extinction of the accurate capacitors. Now it is nearly impossible, if not impossible to find.

The new, hyped, caps one sees today are so ridiculously expensive, and I am not going to shell out for even one, to see how accurate it is via very special listening tests (not the ridiculous tests one sees in articles and on forums). Besides that, everyone will want a different ufd value to be tested. As a result, instead of moving forward, the audio industry has moved backwards.

The only suggestion I have (since the general public are not professionals) without spending thousands, is to purchase virtually every known inexpensive brand, including small bypass values (probably spending hundreds of dollars) and get a feel for each one's sonic's qualities. Over time, one hopefully will learn how to blend caps, including bypass caps, for optimum sound quality.

There is no guarantee that the expensive brands are accurate. They could "sound" thin, too full, depends upon the materials, thickness of foils/metallization, termination techniques, lead diameter etc.

If one brand of capacitor "A" has a darkish tone, lacking in highs, a small value could be placed across "A" cap to improve the highs. It could be the same brand, or another brand. 1/100th is one estimation, but the value should be determined by experimentation.

Sorry I sound so negative, wish I could be of more help mress.

Cheers
Steve
« Last Edit: November 26, 2017, 09:55:20 PM by steve »
Steve Sammet (retired, but manufacturing "V" ics again)

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Offline mresseguie

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Re: Bypass caps....why use them?
« Reply #2 on: November 27, 2017, 08:42:56 AM »
Steve,

Thank you. I know more now than I did when I asked, so it's a plus.  :thumb:
Daedalus Audio Apollos Fritz Loudspeakers LS/5-R
Gustard X20u DAC
dB Audio Labs Tranquility SE DAC w/Jupiter Caps
Don Sachs Model 2
Don Sachs Kootenay 120 KT88; Nuprime ST-10
TWL loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUSS
PI Audio USB cable
Mac Mini

Offline BobM

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Re: Bypass caps....why use them?
« Reply #3 on: November 29, 2017, 05:14:53 AM »
In a crossover you generally get most of the capacitance on the tweeter. Most manufacturers will use one large cap in that circuit, and they won't pay up for the better ones. So you get a large cap that is of mediocre quality at best. That may result in a trimming of the very high frequencies. Using a bypass cap on that large cap may indeed help pass on more air and zing to your sound.

The general rule is to use no larger than 1/100th the value of the large cap, though most people suggest going no larger than .1uF. You can also do this to any electronic component that uses a capacitor coupled output, like a DAC or CD player or preamp. Of course, those generally have values that are smaller, like 1uF, so you could just upgrade the quality of those and be done with it.

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Offline richidoo

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Re: Bypass caps....why use them?
« Reply #4 on: November 29, 2017, 09:42:15 AM »
Good, inexpensive, line level caps are Vishay MKT1813 (yellow, polyester, from Mouser.) Good reasonably priced high voltage caps for tube amps and speakers are Jantzen SuperiorZ (Red, from PartsExpress.)  They are good enough to live happily with them and not know what you're missing, they have no negatives. Sure there are better caps available, to reveal more detail with more refinement. But how do you know you need that until you hear it? = audio addiction.
The ubiquitous Solens are the worst, so many so-called high end components have them.

Something I always wondered: Do parallel caps add any intermodulation distortion due to their individual phase rotations starting at different frequencies? They are connected, so only one net phase on output, but do they fight and leave any IMD residue?