D Sonic DP207 Coil Information

[TheGrateOz]

Thanks again Joe, suggestion taken. Profile updated. Merry Christmas!

[dpm]

That sounds about right, from the similarity of the descriptions. The acid test is to concoct a variable-Q inductor consisting of an iron-cored audio transformer winding (other windings being open) and a 50K pot in series. Measure the inductance at 1000 Hz while varying the series resistance using the pot. The indicated inductance should not vary much until the series resistance is around the reactance at 1000 Hz or greater.

If the LCR meter is not suitable, the effect will not be subtle - a 2 H inductor will soon be reported as 50 H. Many were perplexed until this effect was understood.

Joe, how far from the 2H and 50k formula can I take this test? I've got a 3H humbucker coil with steel slugs here, and 25k or 100k pots but no 50k right now.

[Joe Gwinn]

Joe, how far from the 2H and 50k formula can I take this test? I've got a 3H humbucker coil with steel slugs here, and 25k or 100k pots but no 50k right now.

You cannot use a humbucker coil at all, as its Q will most likely be too low to permit a valid test.

You can use the 100K pot with any reasonable iron-cored transformer or inductor whose inductance is a few Henrys, and whose DC resistance is no more than a hundred ohms or so. This test is pretty robust, so as long as the inductance is in the Henrys and the pot resistance is at least 50 K, I would not sweat the details, as inappropriate LCR meters will flunk dramatically.

[dpm]

Gotcha, thanks. Sounds like a Marshall choke or similar would work - 5H, 115 ohm

[TheGrateOz]

I just so happen to have one in front of me

south coil (bar coil) 7k dc resistance, 3.37H @ 100Hz - coil is far from full so I'm guessing 44awg
north coil 5.25k dc resistance, 2.64H @ 100Hz - coil almost full so 43 or 42awg?

Hi DPM,

Did you happen to take note of the wire type on the 207?

Thanks!! OZ

[TheGrateOz]

Meaning Formvar, Plain Enamel...etc...

[dpm]

No idea, I haven't opened it up.

[TheGrateOz]

Can you tell if it is darker or a bright copper?

[dpm]

Nope, it's all very thoroughly taped up

[David Schwab]

I don't think DiMarzio uses PE. Every one of their pickups I have looked at used poly.

On the 36th Anniversary PAF they say they use "custom-coated wire".

[TheGrateOz]

Thanks guys Have a great new year!