OK guys,
Wondering if somebody wants to take a look at this patent, and voice an opinion if this circuit could make an improvement.
http://www.pandathumbaudio.com/download/Patent1.pdf
At another site, some people said they have used this device, and it improved their system.
Randy
Wondering if somebody wants to take a look at this patent, and voice an opinion if this circuit could make an improvement.
http://www.pandathumbaudio.com/download/Patent1.pdf
At another site, some people said they have used this device, and it improved their system.
Randy
I have only skimmed the patent, but I note a few things:
1. The inventor makes reference to standing waves in speaker cables and interconnects. Well, maybe if you run a mile of cable.
2. No real data is given to support his contention that conventional feedback amps of good design are "unstable."
3. No comparative data is given demonstrating the advantage of this invention, only vague claims of "improved sound" and "improved stability."
4. Testimonials are worthless. Totally worthless. I don't care how nutty or wrong something is, I can find you someone willing to say it works. Like those, ahem, extension pills that I keep getting emails about. Or Alex Chiu.
So, I don't know definitively that this is snake oil, but it sure has that aroma.
1. The inventor makes reference to standing waves in speaker cables and interconnects. Well, maybe if you run a mile of cable.
2. No real data is given to support his contention that conventional feedback amps of good design are "unstable."
3. No comparative data is given demonstrating the advantage of this invention, only vague claims of "improved sound" and "improved stability."
4. Testimonials are worthless. Totally worthless. I don't care how nutty or wrong something is, I can find you someone willing to say it works. Like those, ahem, extension pills that I keep getting emails about. Or Alex Chiu.
So, I don't know definitively that this is snake oil, but it sure has that aroma.
Hi,
Reading the patent text I can not help wondering what is needed in order to get a patent approved in the US?
Is it really allowed to ignore basic proven facts and argue for things that are not true?; (like the rubbish in the beginning of the patent text regarding stabilisation of amplifiers)
Stabilisation of feedback amplifiers is well known and completely understood since the 1940-ties and it is not very difficult for a competent designer to design an amplifier that is unconditionally stable for any load condition.
I can agree that in some cases there has been amplifiers designed that is questionable from a stability point of view, (some Naim amplifiers I recall) but then this design has been a delibirate choice done by the designer or maybe because of his incompetence, however it is not in any way true that currently applied methods for feedback stabilisation is insufficient, this can even be proven mathematically.
Regards Hans
Reading the patent text I can not help wondering what is needed in order to get a patent approved in the US?
Is it really allowed to ignore basic proven facts and argue for things that are not true?; (like the rubbish in the beginning of the patent text regarding stabilisation of amplifiers)
Stabilisation of feedback amplifiers is well known and completely understood since the 1940-ties and it is not very difficult for a competent designer to design an amplifier that is unconditionally stable for any load condition.
I can agree that in some cases there has been amplifiers designed that is questionable from a stability point of view, (some Naim amplifiers I recall) but then this design has been a delibirate choice done by the designer or maybe because of his incompetence, however it is not in any way true that currently applied methods for feedback stabilisation is insufficient, this can even be proven mathematically.
Regards Hans
tubetvr said:
For all practical purposes, you don't really have to prove anything anymore. They're handing out patents for perpetual motion machines as well as granting patents on stuff they've previously granted patents for.
se
tubetvr said:
A lawyer, some money, and a good line of bull will work. It helps to get an examiner who is overworked, doesn't really have any stake in the quality of issued patents, and who isn't terribly competent in his/her area of specialization. I've had some who could barely speak English.
Steve Eddy said:
That dosnt sound very practical!!
Why is that so?
Here you have to pay for an investigation of the application, wheater its really a new idea or not.
Magura🙂
There are advantages and disadvantages to the European system. Advantages include better overall examinations and better patents. Disadvantages are that an inventor gives away trade secrets with no compensation if the patent doesn't issue (this is now partially the case in the US since two or three years ago), the process is prohibitively expensive for little guys, and the rules regarding pre-filing disclosure are onerous.
It looks more like "the Zobel from Hell" than anything else. I sort of lost interest when the parts count started to rival that of the typical amplifier itself. Even if it works, it may fall into category of "solutions to problems no one even knows they have".
On further reflexion it may be a candidate for inclusion in one of the more humorous sections of Doug Self's site.
tubetvr said:
Incidentally, I have seen at least one such patent approved in
Sweden too (I note you are from Sweden), although in this case
it was probably over the head of the patent engineers to realize
that the claim was wrong (and above the head of those applying
for the patent too, I am afraid). It was a claim based on a
common misunderstanding of some basic theoretical computer
science.
slippery serpents
I hold 6 patents relating to digital audio tape technology and I must say I find their text complete gobbledeegook. My original explanations were made infathomable by the patent lawyer even to me!
I think I get the gist of this patent. Amplifiers can exhibit voltage instability at HF (beyond the audio range). These instabilities can be reduced by capacitively loading the output at these HFs, adding ever more capacitance as the frequency of the instabilities increases. In other words a non-linear capacitance is added at HF.
Unfortunately, there is no experimental evidence provided to show this working.
My view is that this is a clever idea but I think that it is half-baked. In general, adding capacitance to amplifiers increases phase lag and makes them less stable. The idea of the Zobel network (cap & resistor in series) is to provide the amp with a defined resistive load at HF. A capacitive load is usually the last thing you want, which is why some designs add a series inductor or series resistor and rely on high L low C speaker cable like Naim does.
The invention seems to ignore dissipation of the energy that gets stored in the capacitor/diode matrix. I would have expected to see some resistive dissipation.
I hold 6 patents relating to digital audio tape technology and I must say I find their text complete gobbledeegook. My original explanations were made infathomable by the patent lawyer even to me!
I think I get the gist of this patent. Amplifiers can exhibit voltage instability at HF (beyond the audio range). These instabilities can be reduced by capacitively loading the output at these HFs, adding ever more capacitance as the frequency of the instabilities increases. In other words a non-linear capacitance is added at HF.
Unfortunately, there is no experimental evidence provided to show this working.
My view is that this is a clever idea but I think that it is half-baked. In general, adding capacitance to amplifiers increases phase lag and makes them less stable. The idea of the Zobel network (cap & resistor in series) is to provide the amp with a defined resistive load at HF. A capacitive load is usually the last thing you want, which is why some designs add a series inductor or series resistor and rely on high L low C speaker cable like Naim does.
The invention seems to ignore dissipation of the energy that gets stored in the capacitor/diode matrix. I would have expected to see some resistive dissipation.
Are you really sure about that ? In Switzerland nothing has to be proofed. You can go and apply for a patent. After some formal checks it eill be granted without search for prior art. They rely on the hope that someone would try to leagally attack a patent if it is consisting of nonsense or prior art. Since many laws in our country are made as EC compatible as possible (in order to make trade with EC countries easier) I assume that this practice must be very close to European practice.
Regards
Charles
patents
My experience suggests that the EU and US patent processes are quite different. Roughly (I'm no expert) the US grants first and relies on lawyers to ask questions afterwards. The EU process requires proof that the invention is novel and hasn't previously been invented. So I think it is considerably more difficult and expensive to get an EU patent grant.
My experience suggests that the EU and US patent processes are quite different. Roughly (I'm no expert) the US grants first and relies on lawyers to ask questions afterwards. The EU process requires proof that the invention is novel and hasn't previously been invented. So I think it is considerably more difficult and expensive to get an EU patent grant.
A patent will set you back approximately 20,000 euro in europe.
How expensive is it in the states?
Magura🙂
How expensive is it in the states?
Magura🙂
Actually, a patent prosecution through the EU can run quite a bit more if a well-funded competitor decides to put you through a lengthy contest.
In the US, someone who writes their own patent can get it through for less than $2K. Get a lawyer involved and a balky examiner and the cost can increase considerably. My US patents have probably averaged $5K or so; I write them, have a lawyer review the claims and handle the mechanics of the prosecution, and do the responses to the examiners myself with lawyer review.
In the US, someone who writes their own patent can get it through for less than $2K. Get a lawyer involved and a balky examiner and the cost can increase considerably. My US patents have probably averaged $5K or so; I write them, have a lawyer review the claims and handle the mechanics of the prosecution, and do the responses to the examiners myself with lawyer review.
$5k,
Thats about a quater what the big companies pay a consultant attourny to put one though.
I'm told that patent law is the toughest part of the bar exam to pass.
Thats about a quater what the big companies pay a consultant attourny to put one though.
I'm told that patent law is the toughest part of the bar exam to pass.
A long time ago I used to get a catalog (JC Whitney?) full of miracle devices which if bolted to the the engine of an old Ford would make unbelievable improvement in fuel consumption and performance. If you carefully selected the right half dozen or so of these you could fill your gass tank of your '53 Ford with water and take the pole position at Daytona!
These things are the audio analog of those automotive miracles if you ask me.
These things are the audio analog of those automotive miracles if you ask me.
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