Bacarso, thanks for some real input on the coupling tradeoffs. Servos make it easier to have a 'good' cap in the circuit that is relatively small (less expensive) and any side effects can be greatly attenuated.
Not a question of price. Question of technology.
You'd choose a fashion designer career.
BTW: most of us, here, know perfectly the behaviors of the various cap technologies. No need for a 30 years old article with your name on it.
Captain Spoke: full power on the reactors: we have to escape from the dangerous gravity of this "ego" black hole...
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Except for something like the capacitors in a power supply is there any reason not to use film caps anywhere else you can physically fit the appropriate capacitor? What happens if you use film caps for decoupling applications on the power rails in an amplifier, are there reason not to do that besides package size if the cap values are very low? I haven't used a lytic in a crossover except for the first one I ever built before I knew better, polypro caps aren't that expensive and adding multiple 100v caps in parallel to get the value you want solves the power rating problems. Inductors are another story all together.
Is there any reason not to use the most appropriate cap?Kindhornman said:
Film caps can often be used but:
- they can be large - it is not sufficient that it be small enough to fit, but also is it small enough not to cause too much capacitive pickup/coupling to adjacent stuff?
- they can be low loss - sometimes the highish ESR of an electrolytic is an advantage - especially for the 'bypass every cap with at least one extra cap' brigade
Yes, as i said: i need 5500µF in my bass speaker compensation network. How to do-it with something else in a reasonable enough way , considering price and size ?
The positive thing is there is a 6.8Ohm in serial with them, so i don't care about their internal resistance and 8 mH of coil in serial, so i don"t care neither with their inductances. The only issue is how they change their capacitances with wear and time.
Esperado, just two things.
Your repeated and uncalled for stabs at someone who is a successful audio designer, still going strong after many decades, are a blemish on your character which I hope you wouldn't want to aggravate by persisting in this behaviour.
The second is that coupling caps make a difference. My source amnesia is horrible, but I think TI did an application paper with listening tests on some serious other thing some considerable time ago, and serrendipitously came to the conclusion that they could hear a cap in the chain. I hope a more organized mind can provide a link.
Your repeated and uncalled for stabs at someone who is a successful audio designer, still going strong after many decades, are a blemish on your character which I hope you wouldn't want to aggravate by persisting in this behaviour.
The second is that coupling caps make a difference. My source amnesia is horrible, but I think TI did an application paper with listening tests on some serious other thing some considerable time ago, and serrendipitously came to the conclusion that they could hear a cap in the chain. I hope a more organized mind can provide a link.
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One anecdote: a prominent loudspeaker designer for JBL whose products were marketed to Japan (primarily) had the need for a large capacitance in a crossover. He placed two electrolytics back-to-back and biased them in the middle with a battery. The current was miniscule so the battery lasted a long time.
But when some of the studies and measurements on specifically bipolar 'lytics by various people, which showed that they were dramatically lower in distortion than biased or unbiased back-to-back normal parts, were brought to his attention, he said I don't care---these sound better. One could conjecture that there may have been some compensatory effects with the given transducer I suppose.
Brad
But when some of the studies and measurements on specifically bipolar 'lytics by various people, which showed that they were dramatically lower in distortion than biased or unbiased back-to-back normal parts, were brought to his attention, he said I don't care---these sound better. One could conjecture that there may have been some compensatory effects with the given transducer I suppose.
Brad
Just ask other people, here, how they feel about this endless self promoting and this condescending way to communicate?
For the "successful audio designer", i had the luck to meet and work with a bunch of brilliant designers in my designer's life, like Peter Walker, Raymond Cooke, Joseph Léon(Elipson), Georges Gogny and Georges Poutot (othophase), Ruppert Neve, etc... and a lot of people even more creative and perfectly unknown. All remarkable for their open mind and modesty.
Notoriety is not a criteria of value, specially when it is about human qualities. I'm thinking to the marvelous J.M. Le clear'ch, at this moment, helping each and every one, never trying to poke himself.
This said, i have a lot of respect about some of the fine designs of J.C.
My jokes were intended to make it clear to John that he would do well to let others praise him. What we would do if he did not do by himself.
Who said the contrary ?
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There is of course the possibility that the Target market lapped that sort of stuff up. Let's face it the Various forms of Everest and K series speakers were targeted at a particular form of obsessive with garrard turntables and sub watt SET amps living in houses with paper walls. Wonderful lunacy.
One could also conjecture that 'more distortion' = 'sound better' - at least for some people, on some types of music. Careful experiment might allow us to distinguish between these two hypotheses.bcarso said:
Which one, Dan? This one?
If so, then the answer is: not really.
"A Bi-polar electrolytic is made in exactly the same way as a polar capacitor, with one important difference. In place of the unformed cathode foil we use a second, formed, anode foil."
Capacitor Sound part 6
C. Bateman, Electronics World December 2002 p.45
Hope this helps
What is the technological difference between non polarized electrolytic caps, and two polarized ones in serial and opposite direction ?
That whole series of Cyril Bateman's is really good.
One conjecture, which I don't recall Bateman enunciating, is that the intrinsic structure of the bipolar electrolytic may alleviate piezoelectric effects.
There, there now, Jan. It's not the end of the world, you know, and you are serious enough for most of us, I think. Certainly serious enough for me. AND you have a great site.
John sometimes behaves like a Sherman tank in a proculan shop.
It has nothing to do with DA in coupling cap aplication. It is nos sample and hold aplication..No AC across capacitor, no DA, no distortion from coupling capcitor.
Connect AC source, series coupling capacitor, load resistor to ground. AC source voltage e.f 2V RMS, capacity 47uf, load to ground 10k. What is AC voltage across coupling capacitor in audio band? Think about. I posted measurement time ago..47uf , 1kohm load, 1V RMS source voltage, distortion under 1ppm.
This might be of interest for those of you into High Def audio. Its advertised as a 'proof-of-concept test for DSD online music distribution' and takes place on the 5th and 11th April.
DSD Live Streaming
DSD Live Streaming
Yes, see Art Dudley's article about 2nd and other harmonic distortion in a recent Stereophile, and especially Keith Howard's lengthy-for-Stereophile letter in the April issue in response to the Dudley. I wrote a fan e-mail to Howard in response. George also posted in this thread a link to an earlier article in Stereophile by Howard, in which he tried to discern any advantages to a Jean Hiraga-style harmonic distortion spectrum and concluded that he always preferred lower distortion. I told Howard about this post and I hope he was pleased that his article still had some traction.
There was also an article in audioXpress a few years ago in which a guy put a simple JFET stage between a couple of IC buffer amps iirc and called it macaroni. He began the piece with a statement reminiscent of the popular nutrition writer Reuben who spuriously demonized fats by declaration, the assertion being that everyone likes distortion---it's just a matter of what kind. I understand that article may have set a record for generating reader comments. I was tempted but demurred.
One thing I've noticed about people who claim to like second: musically, frequently they listen to very simple textures, like a vocalist and piano or trio backup. Thus there is little closely-spaced high frequency energy to produce difference-frequency IM distortion arising from the nonlinearity accounting for the 2nd.
Brad
John, you may have missed it, but these days High End consists to an alarming degree of snake oil purveyors, freeloaders and shady characters. It's been decades since it really led the way to better audio, and I do believe the real talents in that field are now a minority. Which is a pity, of course, but it's not of our doing, I think most of us here would qualify for an "Old School" tag. Most here, as far as I can see, are really trying to do something good.
While your methods have obviously proved to be good, as witnessed by your track record, you need to remember that many roads all lead to Rome. I have come across some not very likely candidates for excellent sound, which nevertheless sent many a "high end" device back home in shame. For a fraction of the price. Unfortunately, this is not a rule, but an occasional event which happens here and there, from time to time, randomly even for companies with excellent reputations.
AS witnessed by the Otala/Lohstroh amp, which you agreed was an excellent performer, the trick is not to make a great amp for $10k, the trick is to make an excelent amp for $500. Of course, you will have to compromise usually on output power because as wel all know, power costs money, always did and probably always will.
Lately, in your posts, much use is made of the idea of "high end". Pray tell, what exactly is "high end", especially today? A red cover cable claiming directivity and Hicks bozone speed of sound? It seems to me that thse days, it's the mid level electronics which should drive the idustry forward, by lifting the stanndards and forcing the wildly expensive devices to be better yet so they can justify their exorbitant prices. And ceratinly they should get back more to the sound than the wild case designs and blue LEDs gallore.
While your methods have obviously proved to be good, as witnessed by your track record, you need to remember that many roads all lead to Rome. I have come across some not very likely candidates for excellent sound, which nevertheless sent many a "high end" device back home in shame. For a fraction of the price. Unfortunately, this is not a rule, but an occasional event which happens here and there, from time to time, randomly even for companies with excellent reputations.
AS witnessed by the Otala/Lohstroh amp, which you agreed was an excellent performer, the trick is not to make a great amp for $10k, the trick is to make an excelent amp for $500. Of course, you will have to compromise usually on output power because as wel all know, power costs money, always did and probably always will.
Lately, in your posts, much use is made of the idea of "high end". Pray tell, what exactly is "high end", especially today? A red cover cable claiming directivity and Hicks bozone speed of sound? It seems to me that thse days, it's the mid level electronics which should drive the idustry forward, by lifting the stanndards and forcing the wildly expensive devices to be better yet so they can justify their exorbitant prices. And ceratinly they should get back more to the sound than the wild case designs and blue LEDs gallore.
Brad, you have a strong point.
I'm also annoyed by the usual demo music, very simple, usually slow pieces, which may be good music, but are anything but representative of everything that's out there. I used to visit wild price tube sellers, and innocently ask to have track No.8 o my Blue Man Group CD played. I got chocking and coffing from both the amps and the usual tiny miney speakers when the guy slams a bass drum with a radious of 8 feet; that lost them a hell of a lot of customers. It's realy their game turned around 180 degrees.
And the sales talk ... Just listen to that midrange, lean and clear. Fine, it is, but I don't listen with separate ears to the bass, mid and treble, my ears want to hear it all at once, with no blurring, and yes, I really do want my bottom two octaves, or at least the bottom one and a half octave.
It's becoming more and more a con game which has little to do with audio.
I'm also annoyed by the usual demo music, very simple, usually slow pieces, which may be good music, but are anything but representative of everything that's out there. I used to visit wild price tube sellers, and innocently ask to have track No.8 o my Blue Man Group CD played. I got chocking and coffing from both the amps and the usual tiny miney speakers when the guy slams a bass drum with a radious of 8 feet; that lost them a hell of a lot of customers. It's realy their game turned around 180 degrees.
And the sales talk ... Just listen to that midrange, lean and clear. Fine, it is, but I don't listen with separate ears to the bass, mid and treble, my ears want to hear it all at once, with no blurring, and yes, I really do want my bottom two octaves, or at least the bottom one and a half octave.
It's becoming more and more a con game which has little to do with audio.
Cap usage to the wise....
Similar problem with metallized film. This is what I found when such C reduction happened: If the cap is not hermetically sealed.... the very very thin alum layer will oxidize and thus leave less plate area.... lower C over time. Either use a better sealed met film or a film and foil.... much thicker plate material. The use of HiEnd leads which are stranded type will/can allow air to get thru between strands. Dont use them.
Regarding the voltage rating..... of course you should be rated at 2X PS rail voltage of the driving PA. With bi-pol or pol the higher voltage ratings are more linear. Also, use the higher temp rating (105C) .... more linear (and longer lasting). Note that if you dont use a high enough voltage rated cap and if that cap is met film..... you will slowly burn away plate area and again the C will decrease over time. I would use 200VDC cap parts in speaker systems.
If you love to see what you can do to lower cap distortion in electro types further..... use two back to back NP types.
Finally, to reduce the amplitude of any DA due to voltage drop across the cap..... use in circuits were the Z is as low as possible. This reduces the time constant associated with the DA recovery voltage.
THx-RNMarsh
Similar problem with metallized film. This is what I found when such C reduction happened: If the cap is not hermetically sealed.... the very very thin alum layer will oxidize and thus leave less plate area.... lower C over time. Either use a better sealed met film or a film and foil.... much thicker plate material. The use of HiEnd leads which are stranded type will/can allow air to get thru between strands. Dont use them.
Regarding the voltage rating..... of course you should be rated at 2X PS rail voltage of the driving PA. With bi-pol or pol the higher voltage ratings are more linear. Also, use the higher temp rating (105C) .... more linear (and longer lasting). Note that if you dont use a high enough voltage rated cap and if that cap is met film..... you will slowly burn away plate area and again the C will decrease over time. I would use 200VDC cap parts in speaker systems.
If you love to see what you can do to lower cap distortion in electro types further..... use two back to back NP types.
Finally, to reduce the amplitude of any DA due to voltage drop across the cap..... use in circuits were the Z is as low as possible. This reduces the time constant associated with the DA recovery voltage.
THx-RNMarsh
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