US Patent 7145392

[Ears]

A while ago I posted a patent from Guytron.
Here is one from Peavey. I haven't examined it in detail but seems similar to using unbalanced anode loads in a differential splitter to generate desired distortion in the power amp.
Gee, you have to be quick to patent the obvious.

[Ears]

The description uses a cathodyne splitter but the claim is not specific to just that type of splitter.
It would be interesting to know how essential the high pass filter (C2 and C3) is to its sound, or whether just an unavoidable consequence of maintaining DC conditions. I suspect it's the latter just dressed up as an additional feature.

[VacuumVoodoo]

This would never pass EU patent examination.
Answer to the question: "How can we make a push-pull amplifier produce even order distortion?" is obvious to anyone who has understanding of how push-pull works. It astounds me that such trivialities can be awarded a patent in US. Especially as the principle is described in a publication cited by the examiner. Ridiculous.

[drz400]

A while ago I posted a patent from Guytron.
Here is one from Peavey. I haven't examined it in detail but seems similar to using unbalanced anode loads in a differential splitter to generate desired distortion in the power amp.
Gee, you have to be quick to patent the obvious.

I do believe this was covered by London Power in their books many years before this "patent"

It still amazes me how Guytron could get a patent on re-packaging what people have been doing for 30 years

[Ears]

I do believe this was covered by London Power in their books many years before this "patent"

It still amazes me how Guytron could get a patent on re-packaging what people have been doing for 30 years

This would never pass EU patent examination... Ridiculous.

Agreed, what exactly is "new" about the circuit? I haven't read O'connor's book on patents (the one with the black cover ) but I would be interested from a review or comments from anyone who has. I know patents are only as strong as the will of the patent holder to enforce them but what say Peavey really do enforce this this one for example? These patents hardly give one cause for confidence in the system.

[Ears]

Here is another suspect one, and it seems to have same examiner


"I claim:

1. A power output amplifier for use with electric guitar comprising a plurality of pairs of output devices arranged in a substantially push-pull-parallel configuration wherein at least two of said pairs comprise devices of dissimilar types and further including a switch means such that the pairs of differing types of output device may be selected to function alternately.

2. A power output amplifier for use with electric guitar comprising a plurality of pairs of output devices arranged in a substantially push-pull-parallel configuration wherein at least two of said pairs comprise devices of dissimilar types and further including a switch means such that pairs of differing types of output device may be selected to function alternately or simultaneously.

3. A power output amplifier comprising:

an output;

first amplification circuitry, selectively coupled to the output, for receiving an input signal, amplifying the input signal to produce a first amplified signal, and applying the first amplified signal to the output;

second amplification circuitry, selectively coupled to the output, for receiving the input signal, amplifying the input signal to produce a second amplified signal, and applying the second amplified signal to the output; and

user-selectable switch, operatively coupled to the first and second amplification circuitry;

wherein the first amplification circuitry comprises one or more output devices of a first type;

further wherein the second amplification circuitry comprises one or more output devices of a second type, which is different from the first type;

further wherein the user-selectable switch has a first position in which the first amplification circuitry is operative and in which the second amplification circuitry is inoperative; and

further wherein the user-selectable switch has a second position in which the first amplification circuitry is inoperative and in which the second amplification circuitry is operative.

4. The power output amplifier of claim 3 wherein the user-selectable switch has a third position in which the first and second amplification circuitry are both operative.

5. The power output amplifier of claim 3 wherein the first amplification circuitry comprises two or more output devices of the first type arranged in a substantially push-pull configuration.

6. The power output amplifier of claim 3 wherein the second amplification circuitry comprises two or more output devices of the second type arranged in a substantially push-pull configuration.

7. The power output amplifier of claim 3 wherein the first amplification circuitry comprises two or more output devices of the first type arranged in a substantially push-pull configuration; and

further wherein the second amplification circuitry comprises two or more output devices of the second type arranged in a substantially push-pull configuration.

8. The power output amplifier of claim 3 wherein the first type is of the group consisting of 6V6 and 6L6 type pentodes.

9. The power output amplifier of claim 3 wherein the second type is of the group consisting of EL-84 and EL-34 type pentodes.

10. The power output amplifier of claim 3 wherein the first amplification circuitry and the second amplification circuit are substantially identical apart from the first type of output device in the first amplification circuitry and the second, different type of output device in the second amplification circuitry. "

[Ears]

To fill in some of your idle moments search for patents! sign up at www.freepatentsonline.com

It has a very good search engine and best of all.... it is free

[Dr-Joned]

Ah- Nothing is free! If you sign up, you've just been entered into the perpetual mailing list.

Try the US site, you only need a plug-in for Windows.

http://www.uspto.gov/patft/index.html

[Ears]

Ah- Nothing is free! If you sign up, you've just been entered into the perpetual mailing list.

Try the US site, you only need a plug-in for Windows.

http://www.uspto.gov/patft/index.html

Thanks for the extra link.
PS I signed up to the other outfit well over a year ago and don't recall ever recieving any mail or spam as a result. touchwood, truly, it seems to be OK.

[skyboltone]

Urban story/myth:
There once was a fellow who noticed that the one and two wheel wheel barrows had no US patents, though they seem to have been in use since God created men.

Never the less he obtained a patent for both and was able to extort royalties from companies manufacturing such tools.

True or not I don't know.

[Andy Le Blanc]

I've seen that peavey pat. in a few places.........things may seem ridiculus
there are many.... many.... many... examples of such patent claim awards...
never underestimate the ignorance of the american consumer.....

[guitronics]

Their is an incredibly intelligent Electronics author, Don Lancaster, who wrote a paper on this patent mess,also an "E - Book".

It's called "The case against patents" and it explains that they're basically a waste of time unless you have Truckloads of money...to tie up in court proceedings.

His website is http://www.tinaja.com/ ,and no;I've never met him nor am I connected with him in any way.

It is great reading....a huge website,on a variety of subjects.

[tjauernig]

Ahh yes, the patented "texture" control. The resultant output sounds arguably class A, but I agree, patentable?

The question is, is the patent defendable in court? Many are not. If they were, MB would be able to shut everybody down. They have dozens of patents on clever ways to use a switch