Electrolytic vs film caps for smaller values.

[abbey road d enfer]

If one trusts the data sheets, one difference among these choices will be that the tan-theta specs for most caps depends solely upon the rated voltage, and not on a CV product. So, to reduce the tan-theta losses, which are basically the real component of the dielectric losses, you want the higher voltage rating.

True, but since increasing capacitance reduces accordingly the voltage across it, it may be that the difference is actually very small...just guessing here.
It's a subject for proper testing, but I don't have access to an AP anymore, and anyway I think it's something for a younger person.

 

[abbey road d enfer]

- it would be good to see if that ends up being an issue or not re. distortion or "sound quality".

Exactly! I can see how dielectric loss would impact amplitude/frequency response, but not how it could represent a marker for distortion, particularly since it's often presented as a single value.
I think that capacitor distortion comes principally (but not exclusively) from electrostriction, which, by modulating the dielectric thickness produces instant capacitance variations. Seems to me this model is consistent with the observations made regarding influence of DC bias.

I'd also imagine that leakage could be different among these choices, as leakage is usually specified as a multiple of the cap's CV product.

Although irrelevant in many solid-state circuits, that's a very important factor for any single-rail design or for phantom powered circuits.

 

[MadJack]

As far as the sound is concerned, I don't want to step onto the audiophoolery territories but generally speaking does a MKS sound better than a lytic?

Yes! A mks sound better than a lytic. Take 100vdc and more. Don't buy 63vdc, they sucks.

 

[abbey road d enfer]

Yes! A mks sound better than a lytic. Take 100vdc and more. Don't buy 63vdc, they sucks.

Comment similar to " I prefer oscietra over beluga". It takes some justification.
What are the test conditions ?
As I have often mentioned, the primary factor of distortion is the voltage developped across the capacitor.
Knowing this, a half-decent designer should dimension capacitance accordingly. Replacing a 1uF film capacitor with a 1uF 'lytic is not good practice, but putting a 10uF lytic would give the same low level of distortion. Of course the turn-over frequency would be different, so, if the role of the CR ciruit is to define it, a film cap is a better choice. If the role of said CR circuit is just to get rid of DC, I wouldn't hesitate using a 'lytic.
Of course, there are other considerations, such as durability and bulk.

 

[Ricardus]

Take 100vdc and more. Don't buy 63vdc, they sucks.

Why? What if 63V is already giving plenty of headroom over the working voltage?

Is this even a real account or a troll?

 

[abbey road d enfer]

Why? What if 63V is already giving plenty of headroom over the working voltage?

It is true that for a given capacitance, the higher the nominal voltage, the lower the distortion.
However, claiming that 63V volt sucks is an unfounded assertion.

 

[JohnRoberts]

It is true that for a given capacitance, the higher the nominal voltage, the lower the distortion.
However, claiming that 63V volt sucks is an unfounded assertion.

In case I haven't said so lately, Abbey is the kind, patient one.....

JR

 

[hildy]

Transformers are still used today and in even different designs. From power supplies to network switches, and routers, to electricity power meters. It is not my fault low end audio only use them as 'audio gimmicks' with inexpensive transformers.

You are not wrong about transformers being used today. I don't think anyone would argue that they are not. I work with digital circuits and see transformers here and there. Great for isolation/coupling. Important to note that digital signals are operating at a very strictly limited frequency. And yes, transformers are great for things like power supplies, which, again, have a very limited frequency range.

 

[ccaudle]

It's a subject for proper testing

I just happened to run across a relevant paper last night while looking for something else:

Capacitor "Sound" in Microphone Preamplifier DC Blocking and HPF Applications: Comparing Measurements to Listening Tests
Author: Gaskell, Robert-Eric
Affiliation: McGill University, Montreal, Quebec, Canada
AES Convention: 130 (May 2011) Paper Number: 8350
Permalink: AES E-Library » Capacitor "Sound" in Microphone Preamplifier DC Blocking and HPF Applications: Comparing Measurements to Listening Tests

"The sonic effect of capacitors in various aspects of audio electronics design has long been discussed and speculated upon. Recent publications have tested many of these theories through rigorous distortion measurements of a variety of capacitor types under several test conditions. One particularly interesting result is a measurable increase in 2nd harmonic distortion for electrolytic and PET type capacitors when a DC bias is applied. This article repeats these measurements for a set of capacitors commonly used in +48V phantom power blocking applications and high-pass filters in microphone pre-amplifier designs. These physical measurements are then compared to the result of double blind listening tests in order to examine the audibility of these capacitor distortions as well as explore their sonic effect on various program materials."

 

[abbey road d enfer]

It's quite predictable that 3rd-order distortion created by capacitance vs. voltage becomes progressively 2nd-order when large DC is added. It's probably the case, and even more pronounced with high-perm ceramic caps.
I wonder if the results of this particular study add significantly to the seminal Cyril Bateman paper.

 

[JohnRoberts]

I've mentioned this before but Sam Groner one of our well respected members researched distortion in electrolytic capacitors and wrote about it.
article he coauthored with Scott Wurcer

Sam's website with lots of smart stuff... his publications

JR

 

[MadJack]

Why? What if 63V is already giving plenty of headroom over the working voltage?

Is this even a real account or a troll?

It's a real account! I'm not a troll.
I'm not english so it's not easy to write a long comment for me.
With a 63v mkt your bass frequency will be 'cut' or lifeless compare to 100vdc mkt.
The same for lytics.
Lytics add grit to your sound. Mkt or mkp are clearer.
Believe me, it's true.
@gyraf @abbey road d enfer : You never noticed this problem?

 

[abbey road d enfer]

With a 63v mkt your bass frequency will be 'cut' or lifeless compare to 100vdc mkt.

Do you have evidence of this? Something like audio files comparing the same circuit with a 63V cap against one with a 100V cap of same construction and same value.

Believe me, it's true.

Audio is science; it's for seers, not believers.

@abbey road d enfer : You never noticed this problem?

No.

 

[Newmarket]

With a 63v mkt your bass frequency will be 'cut' or lifeless compare to 100vdc mkt.
The same for lytics.

You're claiming that there is a significant difference in voltage coefficient between capacitors of the same type and value except for a higher Vdc rating ?

 

[MadJack]

You're claiming that there is a significant difference in voltage coefficient between capacitors of the same type and value except for a higher Vdc rating ?

Yes try it!
A capacitors rated 100vdc 1uf mkt give more beautyfull bass frequency than a 63vdc 1uf mkt.
I ear that in my tube guitar amplier in cathode bypass.
It's a cheap test to do, try it.

 

[MadJack]

Do you have evidence of this? Something like audio files comparing the same circuit with a 63V cap against one with a 100V cap of same construction and same value.

No sorry, I don't produce evidence for my self.

Audio is science; it's for seers, not believers.

Lol. If you don't want to try it, no need to be aggressive.

 

[Ricardus]

It's a real account! I'm not a troll.

I'm not convinced.

I'm not english so it's not easy to write a long comment for me.
With a 63v mkt your bass frequency will be 'cut' or lifeless compare to 100vdc mkt.
The same for lytics.
Lytics add grit to your sound. Mkt or mkp are clearer.
Believe me, it's true.

... because you say stuff like this. ^^

 

[abbey road d enfer]

No sorry, I don't produce evidence for my self.

You're asking to be believed, so you should produce some kind of evidence, unless you're Jesus (even then...).

If you don't want to try it, no need to be aggressive.

I'm not aggressing you, I'm just extremely doubtfull about your assertion.
I've probably made/fixed more guitar amps than you ever put you hands on, so my experience tells me you are either wrong or misleaded.
Are you sure the 63V cap has the same value as the 100V?

 

[JohnRoberts]

I told you guys Abbey was the kind patient one... Don't break him.

JR

 

[Newmarket]

Are you sure the 63V cap has the same value as the 100V?

And same age / use / temp rating ? Everything except the Vdc basically. I guess the 100u is physically larger ?