Amplifier patents index

[Circlotron]

http://www.uspto.gov/go/classificati...tm#C330S083000

Click on the red & white "P" at the start of each line to get a list of links to examples.

[mikeks]

Thanks!

[Geek]

Good to know whos toes I'm stepping on

[jackinnj]

I started this page when I broke my ankle a couple years ago (nothing to do but wait for the heel to heal) -- it has some of the abstracts:
http://www.tech-diy.com/patents_amplifiers.htm

[Circlotron]

Class 381 ELECTRICAL AUDIO SIGNAL PROCESSING SYSTEMS AND DEVICES
http://www.uspto.gov/go/classificati...1/sched381.htm

[audiousername]

Originally posted by Geek
Good to know whos toes I'm stepping on

I don't know about Geek people stepping on patent-holder's toes... but I am rather surprised that some of these patents have toes at all.

The 2nd patent from the first link Circlotron posted, "Vacuum Tube Differential Preamplifier" seemed to quite accurately describe the Western Electric transformer-coupled line driver circuit (well... to me anyway) from... who knows when: two valves mounted in differential with an output transformer. Yet it is an "invention" from... 1998

I am not accusing the patent of being invalid, just rather confused. And I do not want to be sued... Lots of other confusing patents exist as well. I suppose it isn't the aim of a patent to explain the invention clearly, but rather to explain it as vaguely as possible to help protect it.