More madness(?)

[VacuumVoodoo]

Another wacky idea that works really well: replacing screen grid resistors with Zener diodes. In this case 75V/5W per power tube (7868), anode to screen grid & cathode to screen grid B+ supply node. At the same I installed 2x56V in series to drop B+ preamp node from 475V to ca 370V.
What does it do? It changes screen limiter action on fast transients to more fast compressor like behavior. Thus the pick transient is not clipped but reduced in amplitude and let through without choking up. But it also exposes mistakes mercilessly.

[Phil_S]

Whacky wow idea! I don't know how intellectual property works in your country, but I'd try to patent that.

[Reeltarded]

You are an awesome nut, you freaky thinker.

I need ta try this. I'll hand you a fiver at the prescribed meeting place.

[VacuumVoodoo]

Whacky wow idea! I don't know how intellectual property works in your country, but I'd try to patent that.

Nah, I've seen it in old book from before the solid state zeners. They used vacuum voltage regulator, ie electron tube Zener equivalent, like 0A2 0A3 and similar to lower screen grid voltage - no talk about dynamic behavior though in those days. Using Zeners is at best an innovation or modernization. I doubt it would be patentable.
A friend has installed Zeners in a couple recycled amps with excellent results.
There's a discussion on this over on Facebook amp builders group. Pretty heated and funny at times.
Here: https://www.facebook.com/groups/2098777 ... 873184493/
Anyone wanting to use this commercially? - play nice and buy a license. You've seen it here first. Just like the MBV - Master Bedroom Volume now touted by a certain builder as their "invention".

[Firestorm]

Just because it's been published before doesn't mean you can't patent it in the US. Oh wait... Your name isn't Randall.

[VacuumVoodoo]

I know. Patents are worthless unless one can afford to defend them. First thing I learned at the Technology Licensing Office at my Alma Mater. Also, for a patent to be granted an invention must demonstrate a certain level of ingenuity and must not be just a novelty or something obvious to "those schooled in the art". USPATOFF has changed its rules to harmonize with EU and ROTW.

[Reeltarded]

Patent everything here. There are litigators who will work for 99% on the back end, plus you get to sue everyone.

Oh, and you don't have to invent anything but another description for a 100 year old device.

[Leo_Gnardo]

Zeners, also LED's in this application were ideas being kicked around at Audio Asylum say 3, 4, 5 years ago. Also LED's in the cathode of preamp triodes. The idea intrigued me but I never went ahead with any experimentation.

So, a big thank you to VV for bringing this back to all our attention. With a review of what it does for guitar tone. Will have to give it a go.

- - - - - - - -
Miles has described the basis for a current scourge: Patent Trolls. There are a couple of episodes of This American Life devoted to the subject. Would be funny if it wasn't a tragedy. Those episodes can be found I'm sure with a little search. Sorry I don't have a link. Might try WBEZ Chicago Public Radio.

US Pat Off now seemingly will grant a patent to any who write a check. Patentable items for many years now have included intangibles such as various "business methods" and wacky items such as "stick, toy for a dog" Pat. # 6360693. (Now off-patent due to failure to pay maintenance fee. Thank goodness now the patent police won't write you up for playing with your dog.) One of my college apartment mates went to work for the Patent Office and although he wasn't such a bad guy to have to live with*, wasn't exactly the brightest bulb on the tree. If that's the sort running the US Pat Off now, heaven help us. At the moment, seems having a patent on something just gives you a right to attack someone else for using your patented item or idea, and they have to defend by proving "prior art" IOW that the item, circuit, business method etc was in use prior to the application. Also, if an invention has been in use by the public for over one year, theoretically they are not supposed to grant that patent. If you invent a gadget and make a couple, give some to Uncle Elmer, Aunt Matilda, a couple neighbors and friends to try out, and the one year clock runs out, no patent for you. Again, theoretically. This should have ruled out the "stick, toy for dog" patent easily. I think someone did that just to show up the US Pat Off. Now, and for a couple decades running, it's the dog's breakfast.

Things ain't now like they used to be.

* He had a copy of an LP I've been looking for ever since "Watching TV With The Radio On" by Barefoot Jerry, a band made of Nashville studio musicians. Also was friends with the original members of Marshall Tucker Band, all were friends from the same neighborhood. Got to meet Doug Gray in 1998 and he confirmed he remembered the guy. Also lent him my fav. electronics textbook and never got it back. So if anybody has a Diefenderfer out there, I want one.

[Reeltarded]

I used si for cathodes. Was workable but no magic. Dead cat.

[Firestorm]

The USPTO are not rocket scientists and are easily misled by filings that do not adequately address prior art. Once granted, a patent affords the holder the presumption that his claim is correct. An alleged infringer would have to prove the contrary by more than a preponderance of evidence. Therefore, patent everything.

This is a gaping hole in US Patent Law and the courts are looking at it. This will take awhile. Meantime, a perfectly legitimate defense to a patent infringement claim (and a successful one) is "Duh! It's printed right here. How could the PTO be so stupid? "

But you have to pay lawyers.

[Leo_Gnardo]

The USPTO are not rocket scientists and are easily misled by filings that do not adequately address prior art. Once granted, a patent affords the holder the presumption that his claim is correct. An alleged infringer would have to prove the contrary by more than a preponderance of evidence. Therefore, patent everything.

This is a gaping hole in US Patent Law and the courts are looking at it. This will take awhile. Meantime, a perfectly legitimate defense to a patent infringement claim (and a successful one) is "Duh! It's printed right here. How could the PTO be so stupid? "

But you have to pay lawyers.

Poor Randall Smith must be surrounded by a tall pile of his (punctured) balloons then. And the lawyers - always win. I knew I was in the wrong business. Leo Gnardo Esq. Hm. like the sound of that.

BTW the dog stick patent lost traction early as 2006 when I read on further. Still should never have been granted. Guess we need a patent on a patent-filing business method to stir up business for lawyers. Just one rung up the ladder from a toy for dogs. Oh drat. The patent trolls have that.

[Firestorm]

Henry VI.

Nay. Just the other guy's lawyers.

[VacuumVoodoo]

Uspatoff has harmonized procedures with PTC-Patent Treaty Countries.
The inventor is not the individual who invented it first but the one who first submitted patent application. That's how it works. The difference between US and ROTW is that Uspatoff will grant patents on trivialities and "novel application of known stuff" - which is what Randalls patents rely on by claiming "applied to musical instrument amplifier". Now, show me a device that amplifies a musical instrument ie makes it physically bigger.
However: if you disclose the invention at a conference or elsewhere, you have a one year grace period to file a patent for it. This means that your disclosure will prevent someone else from getting a patent on your invention.
The thing to do, if you believe your invention is revolutionary, is to file a preliminary application before you go bragging in public. This establishes your priority.
Anyway, forget this circus started long ago by some Russian immigrant, I mean "Uspatoff" sounds russian to me.
Try this Zener thing, let me know what you hear. The Zeners are from 1N53XX series, nothing exotic.

[Structo]

Thanks Aleks,

Interesting reading and a topic that can guarantee differences of opinion.

I found this article through that forum.
A lot of information about screen grids.

http://www.oestex.com/tubes/screens.htm

[Structo]

Another article explaining that diodes on the screen grids of guitar amplifiers may not be a good idea.

http://www.oestex.com/tubes/oes.html