low impedance low resistance hum canceling coil

[Amplexus]

What is the lowest resistance / impedance dummy coil that can be done that provides an output large enough so as not to introduce too much noise when amplified to single coil levels? Number of turns wire gauge etc. It can be as large as a strat pickguard. I'm looking for one coil that can hum cancel 3 strat single coils without them sounding like humbuckers. Would it be best to wire it in series or parallel or have the option for either one.

[TGD]

What is the lowest resistance / impedance dummy coil that can be done that provides an output large enough so as not to introduce too much noise when amplified to single coil levels? Number of turns wire gauge etc. It can be as large as a strat pickguard. I'm looking for one coil that can hum cancel 3 strat single coils without them sounding like humbuckers. Would it be best to wire it in series or parallel or have the option for either one.

Dummy coil must have similar resistance respect the single coil if you want to have a real humbucker effect, this help you in ground noise releasing. I don't know what kind of preamp are you referring, but I suppose something such a buffer. In this case it permits to boost signal overall frequency band transducted from pickup. Bigger is Q factor and more a flat responce is obtained. Keep in mind that signal can't be splitted from noise; low impedance transductors will release a flat frequency response, in few words a balanced efficiency overall whole pickup frequency response, and it will cause more hiss noise (semi conduction noise coming from active components).
My personal suggestion is to find a good compromise between pickup frequency responce, his Q factor, quality of your buffer components and gain amount. I suggest to use ultra low noice IC, metal resistors and professional capacitors, but often it' s not enough.

Hope it will help you and sorry for my english.

[David Schwab]

Some of the newer stack designs utilize a hum canceling coil with heavier gauge wire and more metal in the core than the string sensing coil.

Also a larger size coil with heavier wire would work well.

You want the dummy coil to be as noisy as possible. If it doesn't induce noise, it can't cancel it from the system.

[Amplexus]

Some of the newer stack designs utilize a hum canceling coil with heavier gauge wire and more metal in the core than the string sensing coil.

Also a larger size coil with heavier wire would work well.

You want the dummy coil to be as noisy as possible. If it doesn't induce noise, it can't cancel it from the system.

David
Any idea how few turns and how heavy of wire? the op amp I am using is a LM4562, which is very clean, which allows for a lot of gain. Bob Pease says it is the best audio op amp ever built.

LM4562
Dual High Performance, High Fidelity Audio Operational
Amplifier
General Description
The LM4562 is part of the ultra-low distortion, low noise, high
slew rate operational amplifier series optimized and fully
specified for high performance, high fidelity applications.
Combining advanced leading-edge process technology with
state-of-the-art circuit design, the LM4562 audio operational
amplifiers deliver superior audio signal amplification for outstanding
audio performance. The LM4562 combines extremely
low voltage noise density (2.7nV/√Hz) with vanishingly
low THD+N (0.00003%) to easily satisfy the most
demanding audio applications. To ensure that the most challenging
loads are driven without compromise, the LM4562
has a high slew rate of ±20V/μs and an output current capability
of ±26mA. Further, dynamic range is maximized by an
output stage that drives 2kΩ loads to within 1V of either power
supply voltage and to within 1.4V when driving 600Ω loads.
The LM4562's outstanding CMRR (120dB), PSRR (120dB),
and VOS (0.1mV) give the amplifier excellent operational amplifier
DC performance.
The LM4562 has a wide supply range of ±2.5V to ±17V. Over
this supply range the LM4562’s input circuitry maintains excellent
common-mode and power supply rejection, as well as
maintaining its low input bias current. The LM4562 is unity
gain stable. This Audio Operational Amplifier achieves outstanding
AC performance while driving complex loads with
values as high as 100pF.
The LM4562 is available in 8–lead narrow body SOIC, 8–lead
Plastic DIP, and 8–lead Metal Can TO-99. Demonstration
boards are available for each package.
Key Specifications
■ Power Supply Voltage Range ±2.5V to ±17V
■
THD+N (AV = 1, VOUT = 3VRMS, fIN = 1kHz)
RL = 2kΩ 0.00003% (typ)
RL = 600Ω 0.00003% (typ)
■ Input Noise Density 2.7nV/√Hz (typ)
■ Slew Rate ±20V/μs (typ)
■ Gain Bandwidth Product 55MHz (typ)
■ Open Loop Gain (RL = 600Ω) 140dB (typ)
■ Input Bias Current 10nA (typ)
■ Input Offset Voltage 0.1mV (typ)
■ DC Gain Linearity Error 0.000009%
Features
■ Easily drives 600Ω loads
■ Optimized for superior audio signal fidelity
■ Output short circuit protection
■ PSRR and CMRR exceed 120dB (typ)
■ SOIC, DIP, TO-99 metal can packages
Applications
■ Ultra high quality audio amplification
■ High fidelity preamplifiers
■ High fidelity multimedia
■ State of the art phono pre amps
■ High performance professional audio
■ High fidelity equalization and crossover networks
■ High performance line drivers
■ High performance line receivers
■ High fidelity active filters