Simply provided via Dirac equation
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Audible difference in high-end capacitors? - ABX samples
- Thread starter ctrl
- Start date
The 'discussion' here and in parallel the DC blocking capacitator thread gives a wide spread of 'opinions'.
As this forum mentions science in it's name, this means discussing results and former improvements.
So I may promote my former question: what's the optimum measurement environment for capcitators by minimized impact of the measurement gear (to keep alligators, tweater's irregularities and that stuff off the discussion), something like source --> cap --> probe?
As this forum mentions science in it's name, this means discussing results and former improvements.
So I may promote my former question: what's the optimum measurement environment for capcitators by minimized impact of the measurement gear (to keep alligators, tweater's irregularities and that stuff off the discussion), something like source --> cap --> probe?
esl 63
Member
Except for inductance and resistance you have dielectric loss, permittivity, and dielectric absorption over a range of frequencies. And those changes with temperature and humidity level and most important the dielectricum choosed. Dielectric absorption can be reduced by adding a DC component on the capacitor. This is most often used with electrolytics but in some industrial measurment equipment and even some audio companies uses this method even for film capacitors.
solderdude
Grand Contributor
But to what measurable and above all audible effect for audio applications (the latter proven and not subjectively found) ?
Seems this proof is not acknowledged here.
Give some source?
MAB
Major Contributor
For example, a real speaker measurement:
H7 is below the noise floor by order of magnitude. Can you hear 0.01% H7?
Put aside if I have a capacitor (or any component) that could boost H7 to a significant level.
Perhaps I need to build a soundproof chamber. Or a worse speaker.
But, let's be real. You are imagining all sorts of supposedly reasonable scenarios, but are actually corner case, as a couple quick measurements show.
OP
- Thread Starter
- #628
Now we're going round in circles again. Distortion of film capacitors plays no role at all in crossover, as it is extremely low and magnitudes lower than the distortion caused by drivers.
For example, take a look at the measurements of film capacitors by Cyril Bateman from 2002/3 - that's how long ago the matter was settled. By the way, @pma has already confirmed these measurements several times and has measured, for example here, harmonic distortion of capacitors at 20Vrms (!!) - 100% inaudible.
The argument of the "capacitor sound" believers at the time (back 2002 and later) was that you can only perceive the "capacitor sound" if you listen to the entire chain up to the loudspeaker, because the decisive factor would not be measured in the purely electrical measurements.
Now we have multiple measurements (made four parts with measurements to "capacitor sound") and here in the thread additional sound samples with pink noise and music, plus the possibilities for valid ABX test and null test possibilities.
What is the reaction of the "capacitor sound" believers? Now the differences can only be determined by electrical measurements...
As you rightly said, HD2 only becomes perceptible at very high levels due to masking (about >1% at 80dB and >2% at 90dB SPL, with single tone masker). It is important that the harmonic distortion of the third and higher order are as low as possible.
In the first part of the mini series I have already shown that multitone distortion (harmonic distortions + IMD) of standard caps and "high-end" caps in crossover at the end of the chain are practically identical.
The next argument is always that your chain wasn't resolving enough. I already showed a measurement of harmonic distortion for the complete chain in the opening post at 90dB SPL.
HD3 is in the relevant range 1-7kHz usually well below 0.1% HD3.
HD4 is below 0.01% HD4 in the relevant range.
All higher orders are even lower.
What does 0.01% HD4 mean and that the higher orders are below it?
The audio sample was recorded at 90dB@1m, 0.01% means that HD4 is -80dB below the fundamental at 90dB (and 0.1% HD3 is -60dB).
A normal listening room has 30-40dB of background noise, so even the 0.1% HD3 (-60dB) is practically lost in the background noise.
But this is not necessary, as 0.1% HD3 is easily masked even in the worst case by a single tone masker - more detail about masking with links to more details can be found here.
I could have made the recordings with a lower SPL, then harmonic distortions would have been even lower, but in the other parts of the mini series there was always the objection that the "sound differences of the capacitors" would only occur at a higher SPL (i.e. voltage) - I have no idea who makes these "rules", but I stick to them to reassure the faithful.
This is all in the inaudible range, with a tweeter that shows even less distortion, it would simply be even less audible.
In contrast, read (in the opening post) through the quotes from the reviews on the "high-end" capacitor used in the sound samples:
It's not about subtle, barely perceptible differences, but about staggering revelations and the more expensive the capacitor, the greater the revelation
The optimum form for testing anything is in situ, in the exact operating condition you're listening in.
I am not entire skeptical of BAD capacitors, but a properly bypassed bipolar 'lytic should be just perfect. If there's a constant DC issue, then a regular 'lytic, also bypassed, should be just as fine.
For entertainment, look at the "linearity" of some of the "silicon capacitors". They're more like batteries.
I am not entire skeptical of BAD capacitors, but a properly bypassed bipolar 'lytic should be just perfect. If there's a constant DC issue, then a regular 'lytic, also bypassed, should be just as fine.
For entertainment, look at the "linearity" of some of the "silicon capacitors". They're more like batteries.
This is a great test and discussion!
There is one reason to "upgrade" the capacitors in a piece of gear. As capacitors age, the capacitance value changes. When repairing and re-tuning older FM Tuners I have found that some 40 year old electrolytics have increased in value by 1.5x. Older types of capacitor don't seem to have this problem. They are also subject to leaking oil as they age.
One should replace all the electrolytics in a system every 15 years or so.
There is one reason to "upgrade" the capacitors in a piece of gear. As capacitors age, the capacitance value changes. When repairing and re-tuning older FM Tuners I have found that some 40 year old electrolytics have increased in value by 1.5x. Older types of capacitor don't seem to have this problem. They are also subject to leaking oil as they age.
One should replace all the electrolytics in a system every 15 years or so.
DonR
Major Contributor
I don't take that approach. Manufacturing quality varies greatly amongst capacitors and device design also plays a crucial role. Some electrolytics are garbage after a few years of use. Some designers insist on placing an electrolytic in or near a hot spot on the device, accelerating aging. Some electrolytics last 50 years or more. I have Spragues from the 70's that still measure well. If the brand is unknown to me or known to be poor, I will blanket replace them though just out of an abundance of caution.
Agree with electolytics and snake oil, though subjective experience, more than 20 years ago, all right, hearing was much better then, did an obvious difference (mentioned above) between lytic and foil capacitator.
Moving over to active control via DSP and D-class amplification this discussion might become unnecessary ....
Capacitor endurance may have been a problem in very old equipment, but modern-day caps have come a long way in reliability and consistency. I have 20-year-old home-brewed vacuum tube power amps that have their original industrial brand-name power-supply electrolytics in them, and I see no need to replace them. How do I know? Because I turn the power amps off first when I power down my setup, and music is playing at low volume when I do so. I notice how long it takes for the music to fade away, and that gives me a good handle on the condition of the supplies' 'lytics. I do not use 'lytics in any other part of the amplifiers' circuitry, so that's all good to go.
because that's science .. and the only way to know for ~sure
and still, there is not much proof/studies that they sound the same either. Just a pretty serious lack of proof, both ways .. and that only means lack of proof.
"Everything sounds the same until proven otherwise" is a good/safe start-hypothesis ... but there is quite a long way from that "start" to a clear "finish".
nope, just thinking that it's not enough.
And btw, your "psychoacoustically-weighted" metric looks very interesting. But it still needs a published/reviewed paper to clarify what/how/why it does, where are the audibility thresholds etc... As-is it has lots of potential but it does not count as proof
Thanks, those are helpful.
Not the most helpful though: multitone graphs are quite hard to (visually) read, one needs a calculator to figure out what all those distortion byproducts are. Also it is ~impossible to visually compare two multitone graphs (unless the diffs are huge).
How about a fullspectrum HD graph? The ones provided by Archimago look pretty nice & easy to read.
Your post/measurements are very useful and many thanks for the effort. But proving inaudibility in a sure/fool-proof manner is not an easy task, it might just be the hardest ever (generally, proving negatives is quite close to impossible).
@ctrl
something that should be added to your first-post: a nice intro-to-caps article.
I would recommend "Thinking Caps" and its biblio: an easy & clear read and it also contains a few thoughts on how they may sound different (e.g. microphonics/vibration sounds like a pretty serious possibility for crossover applications)
something that should be added to your first-post: a nice intro-to-caps article.
I would recommend "Thinking Caps" and its biblio: an easy & clear read and it also contains a few thoughts on how they may sound different (e.g. microphonics/vibration sounds like a pretty serious possibility for crossover applications)
"just thinking" isn't enough to warrant further investigation. Just saying...
Yeah. And for all you guys that obsess about boutique capacitors, the best thing you can do is throw them all away and go active. I doubt even the most expensive capacitor adds a desirable sound.
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