Peter Daniel said:
Just to clarify, I have Epos 11 speakers and Kimber 4TC speaker cable.
Not an easy task for a GC, and my power amp has LM3886s.
I tried zobels, several values of resistor and cap across the output terminals and was not satisfied.
I had bought cheap Supra 2.5 cable to use with my GC, because it gave much better results than the better and much more expensive Kimber.
But I don't quit easily and I thought that if I could get my amp to work with the Kimber, I would gain in sound quality, I know this cable and I like it a lot.
Peter, I had tried previously 0.22 ohm resistors on the output and didn't notice any change, maby because they were bobinated resistors.
The two paralleled 0.47 ohm 3W was a coincidence, because I couldn't find lower value carbon resistors.
I tried it and god
shock, horror, the Krell came back , now my system was singing.Peter, to test this you need (as I have) difficult speakers and difficult cables.
If you get your amp to work well under these circumstances, it will work almost everywhere.
Peter Daniel said:Although your entry is not exactly what I was asking for, it's better than nothing and actually proves my point (that Zobel is not a universal fix). So if you don't have any of those (Brian's) boards, send me your address and I'll send you one
What you were asking for is much worst than what I gave you.
I don't have Brian's boards, I have my boards.
You can send me one (is it only one channel?
), but of course I would be much happier with one of your boxes.
I'll send you a mail with my address.
Re: QUALIFIES? HOW SO?
He was only looking for cases where it was helpful, which Christer found it to be. Neither said the most helpful.fdegrove said:Why do I feel as if the marketing department is being overly generous here?
That's ok... I was just being oddly humorous. Besides, I have no interest in gainclones anyway.Peter Daniel said:
Clever attempt and technically it qualifies. Send me your address
RHosch said:
OK, so he didn't post a link to a previous post but only gave testimony to his experience of a Zobel being helpful in reducing oscillations.
Well, since his post is now a part of this forum history, I hereby post a link to it in full compliance with your original request.
http://diyaudio.com/forums/showthread.php?postid=398248#post398248
That's what I thought when pointing to my own post in this thread
But I think it's generous of Peter to send me a board as well. It's going to be a long summer with all these new goodies.
tx,
Maarten
Re: It depends...
So, isn't that similar to a zobel right there? Doesn't the extended (including cables and speakers) output circuit of the GC sees these?
carlosfm said:My Epos 11 speakers only have a cap and a resistor in series with the tweeter.
Nothing more.
No crossover in the woofer.
That's the Epos way.
High-End.
So, isn't that similar to a zobel right there? Doesn't the extended (including cables and speakers) output circuit of the GC sees these?
Re: Re: It depends...
I'm no crossover expert, but I would say that:
1) the capacitor is there to block DC, and to pass only higher frequencies to the tweeter.
2) the resistor is there to attentuate the sign to the tweeter to match the output level with the other driver in the system, ie woofer...
I very much doubt that loudspeaker manufacturers would build Zobels into their products. They would probably expect the amp to behave itself with "their" load. In other words they won't add the Zobel "just in case" the owner has an unstable amp. I wouldn't expect them too either. Furthermore, the effect of any components at the speaker end of the cable is pretty indeterminate - there's too many possibilities !!!
SteveM
Jamh said:
I'm no crossover expert, but I would say that:
1) the capacitor is there to block DC, and to pass only higher frequencies to the tweeter.
2) the resistor is there to attentuate the sign to the tweeter to match the output level with the other driver in the system, ie woofer...
I very much doubt that loudspeaker manufacturers would build Zobels into their products. They would probably expect the amp to behave itself with "their" load. In other words they won't add the Zobel "just in case" the owner has an unstable amp. I wouldn't expect them too either. Furthermore, the effect of any components at the speaker end of the cable is pretty indeterminate - there's too many possibilities !!!
SteveM
Hi,
Correct on both counts.
I'm not sure how common it actually is but my speakers sure did come with Zobel networks installed right across the speaker terminals on both woofer and midrange sections.
The speakers being 3-way units, the tweeter a purely resistive magnetostat obviously not requiring correction.
In fact that's were I feel these impedance correction networks should belong in the first place.
If everyone would adhere to such a standard, amplifier design would become that little bit easier.
Note that this doesn't solve the speakercable interfacing problem in any way but it helps.
Cheers,
Correct on both counts.
I'm not sure how common it actually is but my speakers sure did come with Zobel networks installed right across the speaker terminals on both woofer and midrange sections.
The speakers being 3-way units, the tweeter a purely resistive magnetostat obviously not requiring correction.
In fact that's were I feel these impedance correction networks should belong in the first place.
If everyone would adhere to such a standard, amplifier design would become that little bit easier.
Note that this doesn't solve the speakercable interfacing problem in any way but it helps.
Cheers,
Re: Re: Re: It depends...
Did you know there's a speaker cable around (MIT if I am not wrong) that has a built-in Zobel in one end?
Even worst: did you know a patent claimed by MIT on such application (filter on cable) was accepted in the USA?
Patent is probably over now, but what would have happened if someone would have released a similar cable? Someone probably did and nothing happened. In any case nobody seems to hear anything on MIT cables anymore.
Carlos
BlackDog said:
Did you know there's a speaker cable around (MIT if I am not wrong) that has a built-in Zobel in one end?
Even worst: did you know a patent claimed by MIT on such application (filter on cable) was accepted in the USA?
Patent is probably over now, but what would have happened if someone would have released a similar cable? Someone probably did and nothing happened. In any case nobody seems to hear anything on MIT cables anymore.
Carlos
I remember some cable of a brand I don't remember (Oracle?) that had big boxes in the middle of the speaker cables.
Those deam big boxes could fit a big toroid inside , so what the hell did they put there?
Just a zobel?
God, people are paying huge amounts of money for fancy cables, some interconnects I've seen have nice wood clamps before the RCAs and inside there's just a ferrite.
Those deam big boxes could fit a big toroid inside
, so what the hell did they put there?Just a zobel?
God, people are paying huge amounts of money for fancy cables, some interconnects I've seen have nice wood clamps before the RCAs and inside there's just a ferrite.
Re: Re: Re: Re: Re: It depends...
All that's required to prevent someone from patenting your invention is to publish the invention. You can take it a step further and file a disclosure with the patent office, but that's not a requirement.
In most of the world the patent application must be filed before public disclosure and the first to file has priority. In the U.S., first to invent has priority, but the filing must be made within a year of public disclosure (even if someone else disclosed the idea), and you have to be able to document when the invention took place.
Back to your regularly scheduled discussion.
Sheldon
Christer said:
All that's required to prevent someone from patenting your invention is to publish the invention. You can take it a step further and file a disclosure with the patent office, but that's not a requirement.
In most of the world the patent application must be filed before public disclosure and the first to file has priority. In the U.S., first to invent has priority, but the filing must be made within a year of public disclosure (even if someone else disclosed the idea), and you have to be able to document when the invention took place.
Back to your regularly scheduled discussion.
Sheldon
Re: Re: Re: Re: Re: Re: It depends...
Well, you are right, but then somebody might try to patent it
anyway and get away with it. It is my understanding that
there has been a number of such cases in the US, at least.
Of course, you can take it to court, but that costs time and
money, and there is said to be at least one case where the
court did not consider well-known academic textbooks a
sufficient publication!!!
A somewhat reversed case is that the state of Bavaria has
the copyright for Hitler's "Mein Kampf", with the explicit
intention to make sure that nobody can publish it.
Sheldon said:
Well, you are right, but then somebody might try to patent it
anyway and get away with it. It is my understanding that
there has been a number of such cases in the US, at least.
Of course, you can take it to court, but that costs time and
money, and there is said to be at least one case where the
court did not consider well-known academic textbooks a
sufficient publication!!!
A somewhat reversed case is that the state of Bavaria has
the copyright for Hitler's "Mein Kampf", with the explicit
intention to make sure that nobody can publish it.
Re: Re: Re: Re: Re: Re: Re: It depends...
I would think that would be a rare instance. I believe it can happen in the case of a foreign publication. But if one was worried about that happening, filing a disclosure would eliminate that possibility. A disclosure filing is inexpensive.
Another interesting item is that holding a patent does not give one the right to make and sell the invention (as in the case of an invention that is an improvement on someone elses patent). It only confers the right to prevent others from producing it.
Sheldon
Christer said:
I would think that would be a rare instance. I believe it can happen in the case of a foreign publication. But if one was worried about that happening, filing a disclosure would eliminate that possibility. A disclosure filing is inexpensive.
Another interesting item is that holding a patent does not give one the right to make and sell the invention (as in the case of an invention that is an improvement on someone elses patent). It only confers the right to prevent others from producing it.
Sheldon
Re: Re: Re: Re: Re: Re: Re: Re: It depends...
There is a possibility that the story isn't true, of course, but it
definitely was a US company patenting something published
in the US. It was a computer algorithm, though, so maybe
that confused both the patent office and the court. As I
remember the story, Lotus got a patent for the Bubblesort
algorithm. It is actually one of the worst sorting algorithms,
so I don't know why they would even bother to patent it,
but it is common in textbooks, so maybe they didn't know
any better one. Anyway, someone else took the case to
court saying that the algorithm was well known since long
ago and was published in Knuth's "The Art of Computer
Programming", which is a standard reference work. The
court did not think that made the algorithm sufficiently
well-known. In the end they agreed howver to restict the
patent to the use of the algorithm in business applications.
What would prevent you from making and selling if you have
a patent? Or do you mean the case where some other patent
overlaps and blocks you from making practical use of it?
Sheldon said:
There is a possibility that the story isn't true, of course, but it
definitely was a US company patenting something published
in the US. It was a computer algorithm, though, so maybe
that confused both the patent office and the court. As I
remember the story, Lotus got a patent for the Bubblesort
algorithm. It is actually one of the worst sorting algorithms,
so I don't know why they would even bother to patent it,
but it is common in textbooks, so maybe they didn't know
any better one. Anyway, someone else took the case to
court saying that the algorithm was well known since long
ago and was published in Knuth's "The Art of Computer
Programming", which is a standard reference work. The
court did not think that made the algorithm sufficiently
well-known. In the end they agreed howver to restict the
patent to the use of the algorithm in business applications.
What would prevent you from making and selling if you have
a patent? Or do you mean the case where some other patent
overlaps and blocks you from making practical use of it?
Re: Re: Re: Re: Re: Re: Re: Re: Re: It depends...
I think that's what he had in mind. If you patent an extension or improvement on an existing patent, and manufacturing the item required use of the prior patent, then you might still be blocked from putting your patent into practical use. All you have done is prevent the prior patent holder from using your improvement. Companies that compete in the same technology field often do this as a way of "hoarding" incremental improvements in SOTA. In many cases, they may not be able to implement their patented technology because doing so would infringe on one held by their competitor, but likewise their competitor cannot implement it either. Kind of a "if I can't do it, neither can you" game.
Christer said:
I think that's what he had in mind. If you patent an extension or improvement on an existing patent, and manufacturing the item required use of the prior patent, then you might still be blocked from putting your patent into practical use. All you have done is prevent the prior patent holder from using your improvement. Companies that compete in the same technology field often do this as a way of "hoarding" incremental improvements in SOTA. In many cases, they may not be able to implement their patented technology because doing so would infringe on one held by their competitor, but likewise their competitor cannot implement it either. Kind of a "if I can't do it, neither can you" game.
Honestly, I did not know. But checked for it now, sounds like immediate classic. Thanks for the info.
EDIT: I’ve found someone using words “nostalgic futurism” for this. I like it.
EDIT: I’ve found someone using words “nostalgic futurism” for this. I like it.
Re: Re: Re: Re: Re: Re: Re: Re: Re: It depends...
It's hard to comment usefully without knowing the particulars of the case. However, you can get a patent on a new use of an old concept - depends on if it would be judged non-obvious to one skilled in the art. Keep in mind that the "art" here is defined by the field of the new application, not the field of the original idea. The vast majority of patents are just new combinations of previously known stuff. In fact, the best patents are the ones where after reading you slap your forehead, and exclaim: "of course, why didn't I think of that?" But if no one had proposed it before and it wasn't a trivial extension of well known stuff, then it can meet the test of non-obviousness, i.e., just because it's obvious when described doesn't make it obvious in the legal sense. The fact that it hadn't been done before in an area where it's clearly useful can be part of the agument for non-obviousness.
It helps to remember that, although laws use common words, those words when used in legal documents have meanings that are very specific and refined by court rulings. Legal use of a word may be somewhat different (usually more limited) from the meanings they have in ordinary usage.
Rhosch answered the second part.
Sheldon
Christer said:
It's hard to comment usefully without knowing the particulars of the case. However, you can get a patent on a new use of an old concept - depends on if it would be judged non-obvious to one skilled in the art. Keep in mind that the "art" here is defined by the field of the new application, not the field of the original idea. The vast majority of patents are just new combinations of previously known stuff. In fact, the best patents are the ones where after reading you slap your forehead, and exclaim: "of course, why didn't I think of that?" But if no one had proposed it before and it wasn't a trivial extension of well known stuff, then it can meet the test of non-obviousness, i.e., just because it's obvious when described doesn't make it obvious in the legal sense. The fact that it hadn't been done before in an area where it's clearly useful can be part of the agument for non-obviousness.
It helps to remember that, although laws use common words, those words when used in legal documents have meanings that are very specific and refined by court rulings. Legal use of a word may be somewhat different (usually more limited) from the meanings they have in ordinary usage.
Rhosch answered the second part.
Sheldon
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