Patents on Parade #1 In this first section of this article we designed a circuit to provide correct impedance and level adjustment between professional audio equipment and an instrument amplifier using some simple circuit parts as shown here: So what is the patent connection? A quick search through the US Patent Office archives online turns up this circuit: Whoa! This is almost exactly the circuit that we designed from the Jensen Transformers application notes (which pre-date the patent application). How is this possible? Can you take old circuit parts and make them into a valid patent... yes, you can. Most anything is possible with the USPTO these days. This circuit was commericalized as the Reamp. Is it valid? You decide. Actually, only the patent court can decide but I would hate to be the lawyer having to defend this patent!