Just to be clear, by "temperature sensitivity," I'm referring to reliability rather than tempco.
syn, what's so special about the PPS caps? It's an OK dielectric and certainly thermally stable, but what does it bring to the table that I wouldn't get with an ordinary polypropylene cap?
syn, what's so special about the PPS caps? It's an OK dielectric and certainly thermally stable, but what does it bring to the table that I wouldn't get with an ordinary polypropylene cap?
I suppose I'm wasting my time suggesting that some folks here try reading these C. Bateman articles on capacitors.
Oh well. One more try.
http://tinyurl.com/bwsh9b
capsound1.pdf -- capsound6.pdf
These are free downloads.
ZAP
Oh well. One more try.
http://tinyurl.com/bwsh9b
capsound1.pdf -- capsound6.pdf
These are free downloads.
ZAP
Hi syn08,
Yes, I agree these days. 10 years or so ago I probably would have disagreed with you. So is the power of the audio press. I'm glad I started testing some before I opened up my mouth!
Hi Andy,
-Chris
Thank you.
Yes, I agree these days. 10 years or so ago I probably would have disagreed with you. So is the power of the audio press. I'm glad I started testing some before I opened up my mouth!
Those are the ones I have been using lately. I don't have an opinion on whether they are better than the others I use, but I can't see anything at all wrong with them. They even look nice, each one looking much like the next instead of some that are "bloby" looking.
Hi Andy,
That is one source that made me reconsider my stance on these capacitors. I think quality may come into play here, much as it does with Mica capacitors. The one thing I don't like about some Ceramics is that they may short around the outside edge. I think that is due to poor manufacturing but I may be wrong there. Man, can they ever burn!
-Chris
zapnspark said:
Yes, those are excellent. Nothing like real data! My quote of Cyril Bateman above was from one of the files on his CD I purchased. It's not in the freebie downloads.
I've heard stories about very good silver mica caps from Germany, here's one: http://www.diyaudio.com/forums/showthread.php?postid=22788#post22788
Hi SY,
Most Polystyrene capacitors die when being soldered in or reworked. Do not resolder these without good reason. It helps a lot to use some type of metal clip between the body of the part and the lead you are soldering. Get it soldered and remove the heat as efficiently as you can. I still use some component lead heat sinks I bought from Radio Shack way back in the 70's. Some early transistors were equally touchy about heat.
I look for capacitors that don't do bad things more than the "drops of pure heaven" these days. Many good capacitors don't sound much different, and they don't appear any different on my THD meter or spectrum analyzer. Some capacitor changes do make a measurable difference on even a THD meter (HP 339A). Even my old Leader THD meter could measure a small but repeatable difference between nasty ceramics (or tantalum) and a better replacement. I figure that I the difference is so small that I have to really work to hear the difference, so will the customer and I'm not about to expose that person to more cost than required.
-Chris
Yes. Sorry, I was unclear also.
Most Polystyrene capacitors die when being soldered in or reworked. Do not resolder these without good reason. It helps a lot to use some type of metal clip between the body of the part and the lead you are soldering. Get it soldered and remove the heat as efficiently as you can. I still use some component lead heat sinks I bought from Radio Shack way back in the 70's. Some early transistors were equally touchy about heat.
I didn't notice anything so far. They are just another possibility when the other types are out of stock for me.
I look for capacitors that don't do bad things more than the "drops of pure heaven" these days. Many good capacitors don't sound much different, and they don't appear any different on my THD meter or spectrum analyzer. Some capacitor changes do make a measurable difference on even a THD meter (HP 339A). Even my old Leader THD meter could measure a small but repeatable difference between nasty ceramics (or tantalum) and a better replacement. I figure that I the difference is so small that I have to really work to hear the difference, so will the customer and I'm not about to expose that person to more cost than required.
-Chris
Hi Andy,
Thank goodness for the test and measurement field! It seems they demanded the parts we require for audio use. That's probably the only reason those parts existed in the first place. I guess I was lucky to have interests in both instrumentation and audio. Otherwise, much of what I learned would not have been available to me.
What more can I say? The T&M industry will always get it right. It's too important to make errors there and that industry has enough cash as a result to do these studies. Far more rigorous standards for the better equipment than audio. Often the required bandwidth is far greater as well.
-Chris
Yes, that was also a good article. I found it later and was relieved to find it re-enforced the views I was coming to accept. I came across that one while building a DVM circuit.
Thank goodness for the test and measurement field! It seems they demanded the parts we require for audio use. That's probably the only reason those parts existed in the first place. I guess I was lucky to have interests in both instrumentation and audio. Otherwise, much of what I learned would not have been available to me.
🙂 😉
What more can I say? The T&M industry will always get it right. It's too important to make errors there and that industry has enough cash as a result to do these studies. Far more rigorous standards for the better equipment than audio. Often the required bandwidth is far greater as well.
-Chris
I wonder what Robert Harley's opinion of NP0 ceramics is? 
Could any high-end designer afford to put such capacitors in his designs without risking the scorn of a bunch of self-important blowhard audio reviewers?
Could any high-end designer afford to put such capacitors in his designs without risking the scorn of a bunch of self-important blowhard audio reviewers?
SY said:
As you said, better temperature stability (e.g. dissipation factor is constant up to 100 degrees centigrades). But one to another an excellent cap that makes teflon look like an unjustified expensive option, together with $1000 power cables and unbleached cotton insulated silver wire. Give me one shred of proof (beyond "sounds good") that teflon is bringing anything special to audio.
andy_c said:
No, of course. Teflon is required, together with unbleached cotton insulated silver wire blessed by Tibetan monks.
As with so many posts criticizing those who listen, I think Andy's point is...shall we say...poorly conceived.
First, a disclaimer: I have no love for Robert Harley. He can take a long walk off a short plank as far as I'm concerned, so please don't get the idea that I'm defending him in particular.
Now back to what I was saying. Does anyone really believe that reviewers actually get catalogs from Mouser, Digikey, Newark, and the various parts manufacturers, then sit around reading them, looking for this part or that in order to demand that the latest and greatest equipment use a Confabulum Capacitor if they desire the coveted Editor's Wet Dream Award?
Checklist for Andy's post: Mockery? Check. Emotion? Check. Righteous wrath? Check. Yes, folks, looks like another message brought to you by the ultra-right wing Science As Religion party.
Ditto for syn08's me-too post.
Grey
First, a disclaimer: I have no love for Robert Harley. He can take a long walk off a short plank as far as I'm concerned, so please don't get the idea that I'm defending him in particular.
Now back to what I was saying. Does anyone really believe that reviewers actually get catalogs from Mouser, Digikey, Newark, and the various parts manufacturers, then sit around reading them, looking for this part or that in order to demand that the latest and greatest equipment use a Confabulum Capacitor if they desire the coveted Editor's Wet Dream Award?
Checklist for Andy's post: Mockery? Check. Emotion? Check. Righteous wrath? Check. Yes, folks, looks like another message brought to you by the ultra-right wing Science As Religion party.
Ditto for syn08's me-too post.
Grey
syn08 said:
No no. It must be Russian (i.e. unobtanium) Teflon for the truly magical effect.
But in all seriousness, Bob Pease's data of DA from 1982 does show that Teflon caps are best for DA. Didn't you post a few pages back that this is a nonlinear phenomenon?
This does get pretty ridiculous at times though. I saw on another site that someone had modified his E-MU 1212M sound card by putting Teflon bypass caps on it. The trouble was, the darned things were about the size of 10uF polypropylene caps, and their inductance probably more than offset any potential gains that might have been possible. Not to mention the diameter and length of the darned things (with axial leads) were so big that there was really no possibility of putting any other expansion card in the computer. But that is what we pay for the "high end", right? 🙂
andy_c said:
DA is essentially nonlinear, but for all practical purposes the model could be linearized. In any practical cap implementation, it is impossible to take the dielectric anywhere close to the breakdown field.
I've posted in another thread some results on the EMU1212M card. It is 2-3 orders of magnitude under any audibility threshold, even with the boards full of cheap electrolytics 🙂
Ceramic caps may or may not be ok today, but my experience servicing says that they will likely as not be ok in a decade or more... guess at my age now that is not as big a design factor as it once was, but I still want my stuff to be operating in 30-40 years, even if I am not.
Ymmv.
_-_-bear
Ymmv.
_-_-bear
syn08 said:
This is making me wonder. In Cyril Bateman's capacitor distortion articles, he establishes correlation between measured capacitor distortion and DA. I was left wondering whether he had fallen for the "correlation vs. causation" fallacy. For some of his tests in which capacitor distortion was easily measurable, he was not able to measure changes in capacitance with voltage. So while conventional distortion measurements have been (rightly IMO) criticized for not relating to audibility, it seems they are very good for "sniffing out" very small nonlinearities.
I have one of these cards in my bench PC. I plan to use it in the configuration Renardson recommends for distortion measurement, so I hope it works out well.
anatech said:
Chris,
point is, those amps enjoyed eargazmic reviews from all golden eared reviewers, despite "big no-no" capacitors in them.
Same reviewers are more or less in the game today, and by all accounts, their hearing ought to be inferior as decades went by 😉
Draw your own conclusions, I already have
Bratislav
Hi Grey,
What do I see? Some good natured ribbing and poking fun at the very things that the average audio reviewer does. It is both funny and sad at the same time. When the average person reads one of these types of "reviews" for the first time, I enjoy watching their facial expressions. You typically get everything from disbelief to WTF??! When someone trained in any branch of physics begins reading these works of art, their response is generally one of annoyance at best. These individuals typically do not get through the entire article. In fact, many freeze within the first paragraph, then read on as if watching a train wreck in slow motion.
Grey, you have to admit that many reviews get pretty silly. More to the point, you can often just change the product name and get a report very close to the one written for that product name you substituted.
You have to understand that the attack was on reviewers, not the fact that you listen to make up your mind. The only one who is being closed minded here is you. You refuse to consider what scientifically valid listening tests can tell you. Also, heaven forbid anyone measures your equipment and assigns numbers to various performance criteria. Listening tests and measurements co-exist and together guide the way to a better design. "Design by ear only" has not been successful in the past and I don't see that changing - ever.
-Chris 😉
That is not at all fair, or accurate. One does not exclude the other, and in fact I believe both measuring and listening are the only responsible way to design anything in audio. The subjectivists here seem to be afraid of measurements, but they don't realize that most audio engineers also consider the listening room just as important as the rest of the process. So, what's the problem here? Are you trying to say that to be a good designer, one must eschew any form of empirical confirmation that what you are doing is the correct course?
Well, what you are saying is closer to the truth than you want to know. They may not rifle through the catalogs to determine the onesy costs on all the parts. They do draw up a list of "audiophile" approved components that they can see. Even wire is not immune from inspection. So you see, they pretty much do what you suggested in jest. They simply do this from the opposite direction. I find that the average audio equipment review is difficult to stomach. I mean, exactly how many veils are our audio systems wearing?? On and on most of these skilled reviewers babble, talking complete nonsense most of the time. Occasionally I will come across a sane person who can explain what they are hearing without using (and mis-using) every adjective they can think of. You can't take the rest of these people seriously.
That is dismissive and arrogant on your part. It's also not true from what I can see.
What do I see? Some good natured ribbing and poking fun at the very things that the average audio reviewer does. It is both funny and sad at the same time. When the average person reads one of these types of "reviews" for the first time, I enjoy watching their facial expressions. You typically get everything from disbelief to WTF??! When someone trained in any branch of physics begins reading these works of art, their response is generally one of annoyance at best. These individuals typically do not get through the entire article. In fact, many freeze within the first paragraph, then read on as if watching a train wreck in slow motion.
Grey, you have to admit that many reviews get pretty silly. More to the point, you can often just change the product name and get a report very close to the one written for that product name you substituted.
You have to understand that the attack was on reviewers, not the fact that you listen to make up your mind. The only one who is being closed minded here is you. You refuse to consider what scientifically valid listening tests can tell you. Also, heaven forbid anyone measures your equipment and assigns numbers to various performance criteria. Listening tests and measurements co-exist and together guide the way to a better design. "Design by ear only" has not been successful in the past and I don't see that changing - ever.
-Chris 😉
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