Abstract: A passive noise reduction device may be used with an instrument having at least one electromagnetic pickup. The device may include a device coil wound so as to form at least one free-shaped ring, a first terminal for connection to the pickup coil, and a second terminal for connection to ground. The device coil is responsive to the one or more stimuli so as to produce a noise electrical signal component in the device coil. The pickup coil and the device coil are in substantially the same plane. The noise reduction device coil is wound such that the pickup noise electrical signal component is substantially 180° out of phase with respect to the device noise electrical signal component, and such that the device noise electrical signal component destructively interferes with the pickup noise electrical signal component so as to reduce noise in a resultant electrical signal into the output circuit.

Abstract: A passive noise reduction device may be used with an instrument having at least one electromagnetic pickup. The device may include a device coil wound so as to form at least one free-shaped ring, a first terminal for connection to the pickup coil, and a second terminal for connection to ground. The device coil is responsive to the one or more stimuli so as to produce a noise electrical signal component in the device coil. The pickup coil and the device coil are in substantially the same plane. The noise reduction device coil is wound such that the pickup noise electrical signal component is substantially 180° out of phase with respect to the device noise electrical signal component, and such that the device noise electrical signal component destructively interferes with the pickup noise electrical signal component so as to reduce noise in a resultant electrical signal into the output circuit.