Forty-Seven Kilohms of Wire That Should Have Been Scrap

Bronze Wire Coil Pickup Winding 🎮 Play: Tight Wind

It’s 3:14am and the multimeter says 47kΩ.

That’s not a typo. Forty-seven thousand ohms. A standard Stratocaster pickup measures around 6kΩ. I’ve wound a coil that reads nearly eight times higher, and I haven’t even finished the bobbin.

Here’s why: I’m not using copper. I’m using the bronze wire left over from the failed textile experiment — the stuff that snapped on draw six, riddled with invisible damage, sitting in a jar marked “probably useless.” Phosphor bronze has roughly 12 μΩ·cm resistivity versus copper’s 1.7 μΩ·cm. Eight times the resistance per unit length. Which means eight times the DC resistance for the same number of turns.

This changes everything about how the pickup voices.

The resonant peak, briefly

Every electromagnetic pickup has a resonant frequency — the point where inductance and capacitance interact to create a peak in the frequency response. The formula is the same one you’d use for an LC circuit:

f = 1 / (2π√LC)

But there’s a catch. Real pickups have resistance in series with that inductance, which adds damping. The damping factor Q is approximately:

Q ≈ (1/R) × √(L/C)

Higher resistance means lower Q, means a broader, flatter resonant peak. Copper pickups have sharp peaks — that “quacky” single-coil character is literally the resonance ringing. Bronze pickups damp that peak into a broader hump. Less sparkle. More midrange. The frequency response looks like jazz.

I didn’t plan this. I was just trying to use up the damaged wire.

Why bronze can even work

The magnetic circuit doesn’t care what the coil’s made of. Copper, bronze, silver, gold — all weakly diamagnetic, all transparent to the magnetic field. The coil’s job is to convert changes in magnetic flux into voltage via Faraday induction. Any conductive wire does this. The tone depends on the electrical characteristics of the coil and whatever you plug it into.

The wire I’m using is roughly 28-gauge, though “roughly” is doing heavy lifting. Hand-drawn wire varies ±15% in diameter along its length. Where I didn’t anneal properly, the cold-worked sections measure slightly higher resistance — dislocations scattering electron flow. The coil’s inductance isn’t uniform either, since inductance depends on cross-sectional area. Different sections contribute unequally to the total.

This is chaos. Deliberate, accidental chaos.

Guitar pickup winders call intentional irregularity “scatter winding” — crossing patterns, varied tension, avoiding neat parallel layers. It reduces inter-turn capacitance and brightens the high end. What I’ve got is scatter winding’s deranged cousin. The wire itself varies, the tension was inconsistent because bronze work-hardens and stiffens as you wind, and I lost count of turns around 2am and just kept going.

The actual build

Bobbin: a 3D-printed cylinder, 12mm diameter, 8mm tall. I’d have used a proper Fender-style flatwork but I don’t have any and it’s 3am.

Magnet: a 10mm × 5mm N52 neodymium disc, press-fit into the bobbin’s centre hole. Neodymium is overkill for guitar pickups — the string pull would be ridiculous — but I’m not putting this near strings. I’m putting it under a singing bowl.

Winding: freehand, guided by thumb pressure, roughly 4,000 turns. The first 500 were neat. The rest are a bird’s nest. When the wire kinked — three times — I cut the damaged section and twisted in a splice. Each splice is a tiny discontinuity in the coil’s electromagnetic behaviour. Each one adds character. Or noise. Probably both.

The tricky part is the lead wires. Bronze doesn’t wet with standard lead-tin solder. You need silver-bearing solder and a flux designed for non-ferrous metals. Even then, the joint between bronze coil and copper lead creates a thermocouple — dissimilar metals in contact generate a small voltage proportional to temperature. Keep the two junctions at the same temperature and the effect cancels. Let one warm up from handling while testing and you get mysterious DC offset in your signal.

I discovered this at 2:30am when the oscilloscope showed a slow drift I couldn’t explain. Touched the input jack, drift accelerated. Left everything alone for ten minutes, drift settled. Thermoelectric effects. The physics is relentless.

Does it actually work?

The cracked singing bowl — one of the semicircles from the hammering disaster — still has enough ferromagnetic impurity to couple with a strong magnet. Sand-cast bronze picks up trace iron from the casting sand. Not much, but enough. When I position the pickup under the bowl fragment and tap it with a wooden dowel, the oscilloscope shows a waveform.

It’s not loud. Even through a guitar amp cranked to distortion, it’s quiet — the output is maybe a tenth of what a copper pickup would produce. But the tone is… odd. The attack is soft. The sustain is woolly. The harmonics that should ring out are smeared into each other, damped by that high resistance, filtered by that chaotic winding.

I have no idea if this is good. I can’t tell anymore. It’s 3am and I’ve been listening to the same dying ommm through a Marshall for two hours and everything sounds either profound or meaningless.

The kalimba tines should work better — steel, definitely ferromagnetic, closer coupling. I’ll try that tomorrow. Tonight the bronze has given me exactly what it promised: unpredictability. A transducer that hears differently than any pickup I could buy. Whether “differently” means “better” or just “wrong” is a question for daylight.

The coffee’s cold. The multimeter still says 47kΩ. Somewhere in those 4,000 turns of damaged wire is a frequency response curve that no spec sheet will ever describe.