Electrolytic vs film caps for smaller values.

[MadJack]

Wow! Your are amazing! Calm down please! You don't like what i said, ok. I apologize. You think i don't have any experience in electronics, nevermind.
But i have already designed about 100 circuits by my own in 22 years. (it's just my hobby) it's not so bad, no?
I don't want fight. Keep cool men!

 

[abbey road d enfer]

You don't like what i said, ok.

It's not a matter of "liking". It's just that you claim things and show no proof.

You think i don't have any experience in electronics, nevermind.
But i have already designed about 100 circuits by my own in 22 years.

It's not either a matter of who you are. When you say something that is against what many people think, you should have some kind of evidence.

 

[57sputnik]

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."

Also from Gaskell regarding coupling/HPF capacitors:

Results were not significant enough to make any statements about their sonic effect. In all the DC blocking (f-3dB < 20Hz) tests, listeners could not perform better than chance. The HPF tests (f-3dB = 72 Hz) used .22uF caps and a 10kΩ load. Many listeners felt they could perceive differences but they could not identify these differences with statistical consistency. It was found that when a large amount of equalization boost was applied in or around the reactivefrequency range of the capacitor, differences could be heard with consistency. Listener reaction was primarily that the capacitors with higher distortion sounded brighter but due to the severe amount of EQ applied it is hard to make good qualitative judgments. The low audibility of the distortion produced by HPFs is possibly the result of masking. Fielder and Benjamin [3] suggest that low-frequency distortion has a much higher perception threshold than the same distortion series applied to higher frequencies. It would be interesting to look at the effects of selecting a higher HPF frequency or the use of smaller value capacitors for the same filter frequency.

"Load" capacitors had some audible differences:

Listeners often considered the higher distortion capacitors to sound more immediate, closer, more open, and more detailed. The less distorted capacitors were often referred to as dark, muffled, recessed, and narrow in comparison. While most listeners seemed to focus on the high frequency differences, some did commend the PET and PPs for having thicker, fuller low and mid ranges relative to the higher distortion electrolytics. Most listeners sighted the more transient sounds as providing the important cues for their discriminations particularly snare drum, harpsichord, tambourine, shaker, acoustic guitar, and vocal sibilance.

As JR says YMMV...

 

[abbey road d enfer]

Also from Gaskell regarding coupling/HPF capacitors:

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

These comments reinforce my suspicion that a large contributing factor in capacitor distortion is mechanical, as I suggested in post #122.
In this respect, electrolytics would be characterized by very large electric Field and soft dielectric - it would be instructive to investigate differences between solid and gel electrolyte - and film/foil types by their non-homogeneous construction.

 

[Newmarket]

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.

Is it easy ? Well to test along same lines as yourself it seems you need a valve guitar amp that is easy to work on. Many people don't have that.

 

[MicUlli]

Its quite interesting following the discussion in this thread IMHO one should always return to the basics of physics. If there is an audible difference between a 1uF/63V and a 1uF/100V cap of the same construction principle (here MKT) the question whether the capacitances are equal arises...

 

[JohnRoberts]

In case I haven't said so lately, electrolytic caps are undesirable for audio filter poles within human hearing range. This is difficult to avoid for passive loudspeaker crossovers. DC blocking is generally transparent if cutoff frequency is set suitably low. Another circuit node difficult to avoid is in series with low resistance gain pots.

In general, very audible differences are most likely evidence of faulty components.

Double blind listening tests carried out to statistical significance are time consuming and boring. I prefer null testing but even that is not trivial.

JR

 

[Mr. Moscode]

Ok film folks. Here's a page from a polypropylene cap technical sheet showing variables with different types of film dielectrics. The pdf is polypropylene_phc_ba1f6d3e0f-2889084.pdf and available at Mouser. Dissipation factor shows actual energy loss in the capacitor and is generally higher in AL 'lytics. Not something I want in an audio chain, info lost forever. Anyway here's the page. Download the whole spec sheet for very detailed explanations of important parameters of various film caps, even though it's a polypropylene cap spec sheet. Those caps sound pretty good, though. Just large.

 

[Mr. Moscode]

I'm not convinced.


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

I tend to side with MadJack. MJ's a musician, that counts in audio evaluation. He's spent time listening with a musically trained ear. However, that said, to be convincing that that rule applies to all caps mentioned, MJ has not done a batch of blind testing, as far as we know.

We had a Dumont B+W tv for many years in the 50s and 60s and I learned electronics on that set keeping it going. It had a 10 inch speaker. I decided to experiment with different audio output tubes since my father had accumulated quite a few scavenging TV's for parts. A 6V6, I think. Anyway I wanted to see what happened when I subbed other tubes in that spot. One of the tubes I put in resulted in quite a bass boost and I couldn't explain it at 10 years old but I could hear it. None of the others did. Maybe today I could figure it out, but that's all in the dear departed past. RIP Alan B Dumont.

The point is it was obvious to me as it is to Mad Jack. If it was something I were to offer to customers I would have to make sure it is repeatable. Mad Jack also describe the sound of 'lytics as adding grit, ie overtones that add character to the sound.

I submit that everything's a filter, everything, to some extent will filter audio. To some more perceptible than others and some are more perceptive to the effects than others.

Anyone who says otherwise is itching for a fight!

 

[MadJack]

Thank you Mr. Moscode!

 

[MadJack]

Ok film folks. Here's a page from a polypropylene cap technical sheet showing variables with different types of film dielectrics. The pdf is polypropylene_phc_ba1f6d3e0f-2889084.pdf and available at Mouser. Dissipation factor shows actual energy loss in the capacitor and is generally higher in AL 'lytics. Not something I want in an audio chain, info lost forever. Anyway here's the page. Download the whole spec sheet for very detailed explanations of important parameters of various film caps, even though it's a polypropylene cap spec sheet. Those caps sound pretty good, though. Just large.

I think that this phenomenon that I have perceived can be explained more simply than by temperature variations.
But you are right Mr. Moscode! The truth is in the datasheet!
I say no more about that.

 

[abbey road d enfer]

Does anyne have evidence that dissipation factor correlates with degraded sonic quality?
Can anyone say that passing signal in a modest voltage divider alters quality significantly?

 

[Newmarket]

Mad Jack also describe the sound of 'lytics as adding grit, ie overtones that add character to the sound.

I submit that everything's a filter, everything, to some extent will filter audio. To some more perceptible than others and some are more perceptive to the effects than others.

Anyone who says otherwise is itching for a fight!

A filter does not add harmonics / overtones.

 

[MadJack]

A filter does not add harmonics / overtones.

Do you have evidence of this?

 

[Ricardus]

I tend to side with MadJack. MJ's a musician, that counts in audio evaluation. He's spent time listening with a musically trained ear. However, that said, to be convincing that that rule applies to all caps mentioned, MJ has not done a batch of blind testing, as far as we know.

We had a Dumont B+W tv for many years in the 50s and 60s and I learned electronics on that set keeping it going. It had a 10 inch speaker. I decided to experiment with different audio output tubes since my father had accumulated quite a few scavenging TV's for parts. A 6V6, I think. Anyway I wanted to see what happened when I subbed other tubes in that spot. One of the tubes I put in resulted in quite a bass boost and I couldn't explain it at 10 years old but I could hear it. None of the others did. Maybe today I could figure it out, but that's all in the dear departed past. RIP Alan B Dumont.

The point is it was obvious to me as it is to Mad Jack. If it was something I were to offer to customers I would have to make sure it is repeatable. Mad Jack also describe the sound of 'lytics as adding grit, ie overtones that add character to the sound.

I submit that everything's a filter, everything, to some extent will filter audio. To some more perceptible than others and some are more perceptive to the effects than others.

Anyone who says otherwise is itching for a fight!

You're describing the placebo effect perfectly. If your evidence is "I could hear it but no one else could" it's not evidence.

I am ABSOLUTELY certain you could hear i when you knew which was which.

 

[abbey road d enfer]

Do you have evidence of this?

A filter may change the spectrum of harmonics of a signal, but if it adds harmonics, that means it's unperfect.

 

[abbey road d enfer]

Do you have evidence of this?

In your post #136, you wrote "No sorry, I don't produce evidence for my self.".
Why are you asking others to do things you don't want to do?

 

[JohnRoberts]

Ok film folks. Here's a page from a polypropylene cap technical sheet showing variables with different types of film dielectrics. The pdf is polypropylene_phc_ba1f6d3e0f-2889084.pdf and available at Mouser. Dissipation factor shows actual energy loss in the capacitor and is generally higher in AL 'lytics. Not something I want in an audio chain, info lost forever. Anyway here's the page. Download the whole spec sheet for very detailed explanations of important parameters of various film caps, even though it's a polypropylene cap spec sheet. Those caps sound pretty good, though. Just large.

The KP dielectric looks pretty good.

JR

 

[Mr. Moscode]

You're describing the placebo effect perfectly. If your evidence is "I could hear it but no one else could" it's not evidence.

I am ABSOLUTELY certain you could hear i when you knew which was which.

You added " no one else does," MJ and I didn't say it. An example of an imperfect filter.

 

[Mr. Moscode]

A filter may change the spectrum of harmonics of a signal, but if it adds harmonics, that means it's

You are correct. This discussion wouldn't exist if all caps were perfect.