Creamery Sonic Six Strat Pickup

[aquin43]

The Creamery (https://www.creamery-pickups.co.uk/) Sonic Six fingerboard position Strat pickup has threaded adjustable magnet poles of 5mm diameter. The magnet material is FeCrCo, which has similar properties to Alnico5.

Since it was so easy to remove the magnets the response was measured both with and without:

The higher peak is without the magnets. There is some eddy current loss due to the magnets but the Q remains high. The kinks in the response between 30 and 40 kHz are not easily explained in a single coil pickup. The change in inductance is small, confirming the low permeability of the magnet material.

The response with 470p 200k parallel loading:

Still a fairly high peak and the high frequency kink is unaffected by the loading. It does occur where the attenuation is high so perhaps that is to be expected.

The dc resistance is 6k508 and the low frequency inductance seems to be best modelled at about 2.3H

The measurement data are at www.aquinaudio.co.uk/DD/Creamery.zip

Arthur

[antigua]

Thanks, this is interesting. The Q is definitely higher than AlNiCo. I never see a +19dB at resonance with AlNiCo pole pieces, it's closer to +12dB, and with 200k load, closer to +5dB instead of +7dB.

The conductivity must be lower, for sure. I wonder if the conductivity of "Iron Chrome Cobalt" and "Aluminum Nickel Cobalt" is basically an average of the conductivity of the constituent metals, or if they way they're alloyed has some effect on conductivity also. 

According to this www.smi-mag.com/FeCrComagnets.html and this www.smi-mag.com/Alnicomagnets.html , FeCrCo comes in a variety of strengths, but overall the Br and Hc tend to be closer to AlNiCo 5 than 2 or 3. I wonder what the gauss readings would show if you had a magnetometer  to check them with. 

[aquin43]

Sorry, no magnetometer.

I forgot to mention that the test set load on the pickup is 10Meg and 17pF

Arthur