Well, I've found it very relevant to myself - "good" recordings are hopeless for picking playback problems, I've found - far too easy to mentally "ride" over the little variations that are noticeable - but use a "poor" recording where some "deficiency" screams at you every time you hear it normally - and the impact of changes are obvious. A good example is where sibilance is irritating - the slightest improvement or degrading of sound quality will stand out clearly, makes the job of moving forward quite straightforward ...
I was meaning at 1MHz and up. I've never actually seen measurements of electrolytic impedance in the MHz range before. I'm curious what the losses look like, if the ESR remains constant up to 10MHz or so.
The Black Gate ad said that electrolytics go "dead" above 200MHz. I'm curious about that too, but at the same time I'm wondering who would try to use a lytic to filter frequencies that are only typically filtered well by feed-thru caps?
Then again there is another argument for "T-network" electrolytics, which to me are a sort of feed-thru cap. Based on the graph here though, they don't do better than a line array of smaller caps would:
DNM Products - Capacitors (overview)
And what about "slit foil" electrolytics? I haven't seen any measurements at all, yet they are made by Kemet along with the T-network caps:
http://www.kemet.com/Lists/ProductCatalog/Attachments/388/KEM_A4029_ALC10S.pdf
http://www.kemet.com/Lists/ProductCatalog/Attachments/79/F3304_ALN20S.pdf
It makes sense to me that in the inductively swamped region of operation eddy current may raise resistive loss in a skin-like effect. Apparently people are willing to pay for these caps yet I can't find any measurements. Of course if you decrease losses in the inductive region, this will only worsen the resonance with any film cap placed in parallel, so it may have the opposite effect intended unless you have a full working knowledge.
The Black Gate ad said that electrolytics go "dead" above 200MHz. I'm curious about that too, but at the same time I'm wondering who would try to use a lytic to filter frequencies that are only typically filtered well by feed-thru caps?
Then again there is another argument for "T-network" electrolytics, which to me are a sort of feed-thru cap. Based on the graph here though, they don't do better than a line array of smaller caps would:
DNM Products - Capacitors (overview)
And what about "slit foil" electrolytics? I haven't seen any measurements at all, yet they are made by Kemet along with the T-network caps:
http://www.kemet.com/Lists/ProductCatalog/Attachments/388/KEM_A4029_ALC10S.pdf
http://www.kemet.com/Lists/ProductCatalog/Attachments/79/F3304_ALN20S.pdf
It makes sense to me that in the inductively swamped region of operation eddy current may raise resistive loss in a skin-like effect. Apparently people are willing to pay for these caps yet I can't find any measurements. Of course if you decrease losses in the inductive region, this will only worsen the resonance with any film cap placed in parallel, so it may have the opposite effect intended unless you have a full working knowledge.
I'm not very familiar with what you call imperfections so I don't connect very well, but if there's a point at which you get into the sound and don't notice the audio equipment, then I'd say that's very normal.
I'd say that something like 75% of the earths population doesn't really listen to audio equipment or the quality or the recording quality, they just listen to the music itself, in pretty much any way, shape or form.
Anyway here is a study on noise, it may interest you
Experimental Study : Distortion - Axiom Audio
Yes, they titled it distortion and keep calling it distortion, but they are very clear at the end of the test they were testing noise.
"The tests done in this experiment are essentially noise tests
///
other types of distortion such as Harmonic Distortion and Intermodulation Distortion have a direct relationship to a frequency being reproduced as part of the music.
///
These types of distortion may be harder to detect than straight noise distortion, a subject for a future round of experiments."
I think the most amazing part is their hypothesis in the last sentence there.
Thanks, Kastor, I'm very familiar with that study - the key point is that the higher the frequency the more sensitive we are to distortion, noise - which is exactly what my own experiences bear out.
Imperfections? Normal audio is riddled with them, try raising the volume to near realistic levels for a drum solo, or an energetic piece of Chopin, and tell me you can't hear "imperfections"! It only takes a single hearing of a system, just one, do such correctly to realise how much nonsense is written about what things are important, or not - and how hopeless most systems are at getting key things right ...
One can listen to music, any time, at any quality level; but most of the time the music is "smaller" than the place where you're listening to it; it's when the music gets "bigger", much bigger than your listening space - that's where the magic is ...
...
Imperfections? Normal audio is riddled with them, try raising the volume to near realistic levels for a drum solo, or an energetic piece of Chopin, and tell me you can't hear "imperfections"! It only takes a single hearing of a system, just one, do such correctly to realise how much nonsense is written about what things are important, or not - and how hopeless most systems are at getting key things right ...
One can listen to music, any time, at any quality level; but most of the time the music is "smaller" than the place where you're listening to it; it's when the music gets "bigger", much bigger than your listening space - that's where the magic is ...
...Out of interest why would you want to use an electrolytic at RF frequencies, just the parasitic inductance of the leads and electrodes makes them all but useless, and the values available are generally larger than one would use at higher frequecies. For filtering there are much better and smaller devices available.
As for lead parasitics, the same can be said of most film capacitors used in circuits here. Feed-thru caps would be one such "smaller device" as I said previously.
Kemet obviously thinks it is worth it to manufacture "slit foil" electrolytics, but I can't find information on what exactly makes them better.
Here you have measurement up to 100MHz (look at the unparalleled data).
http://www.diyaudio.com/forums/powe...lm-caps-electrolytic-caps-17.html#post2257381
Note that it is just a very small part of the measurements I have done.
There is nothing preventing elco's working at many MHz, they don't "go dead" at some frequencies, unlike ferrites for instance, but the problem is simply geometric: the sheer length of the minimum current path is sufficient to add a few nH, and in this respect they cannot compete with microscopic SMD format caps
For some possible insight, Patent US5793602 - Low impedance capacitor - Google Patents.
Surface mount devices, no leads.
Again in what way or part of a circuit would you use a relatively high value elec with RF, they wont really filter because of the inductance?
SMD devices Frank, at RF its parasitic inductance that is the killer so SMD rule here.
Wow Elvee, that is some epically useful and demonstrative data. I know that electrolytics are mainly inductive above 1MHz, that much is obvious. What's funny is that when someone says "electrolytics are no good at RF", I see a lot of people use through-hole film caps instead which often have even more inductance than the electrolytics!
Frank, that patent doesn't show "feed-thru" construction as I had hoped, just 4-wire terminations. This explains why the benefit for T-network caps (not the same as slit foil) is there but not very large. It's a bit disappointing and doesn't seem to make much sense when there are much better options to improve filtering. Now a real feed-thru electrolytic, I'd really like to see.
Still there is the question of slit foil construction and exactly what it's measured benefits are.
Frank, that patent doesn't show "feed-thru" construction as I had hoped, just 4-wire terminations. This explains why the benefit for T-network caps (not the same as slit foil) is there but not very large. It's a bit disappointing and doesn't seem to make much sense when there are much better options to improve filtering. Now a real feed-thru electrolytic, I'd really like to see.
Still there is the question of slit foil construction and exactly what it's measured benefits are.
That's the same question I asked earlier, I guess it just confused me how so many people here seem to care how electrolytics behave at 10MHz and above. It was just so obviously mistaken for me that I had to confirm it here.
So the answer is, electrolytics are all completely inductive at RF. Not dead, just very inductive, and worrying about the RF filtering ability of a lytic is ridiculous when we have SMD and feed-thru capacitors.
Keantoken, you might find this post interesting (as well as the whole thread): http://www.diyaudio.com/forums/power-supplies/226070-network-analyser-measurements.html#post3340903
I can't compete with Elvee, though ;-)
I can't compete with Elvee, though ;-)
NOiSE, yes, not distortion which is totally different, the title itself is deceitful iMHO.
I use these :Mundorf - Inner Excellence
I am happy with the result but why that is i did not research in detail.
I also used DNM slit foils.
I am a friend of Dennis Morecroft. the inventor.
He told me it is because it avoids eddy currents.
I do not have any data though.
This needs more research i guess.
I am happy with the result but why that is i did not research in detail.
I also used DNM slit foils.
I am a friend of Dennis Morecroft. the inventor.
He told me it is because it avoids eddy currents.
I do not have any data though.
This needs more research i guess.
Jensen makes them too :https://audio.jensencapacitors.com/public/dokumenter/4pole.pdf
They also supply some data.
They also supply some data.
It should be more effective to replace that T-network cap with a line of cheap 1000uF electrolytics. The filtering will be much better. The claim is a superior electrolytic, but the actual result is still not very good compared to an array.
The Jensen data shows more of an improvement than the DNM data, in ESR but not in inductance. The ESR would seem to rival that of an array, but not the inductance.
The Jensen data shows more of an improvement than the DNM data, in ESR but not in inductance. The ESR would seem to rival that of an array, but not the inductance.
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