Bare Knuckle Pickups Forum
Forum Ringside => Tech => Topic started by: Skilpad on December 10, 2013, 11:18:09 AM
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Hi,
I am wondering about wiring choices, like using twisted wires or not, which wires...
Basically, one of the main issue is parasitic capacitance. Too much of it may reduce the pickups brightness.
Does anyone know what are the typical value for:
- the shunt capacitance of a BKP humbucker (or, better, one of its coils),
- the parastic shunt capacitances of a potentionemeter?
Using twisted wires may add parasitic capacitances up to 50pF in my case; and even when doing the math, I cannot say if it is bad without the previously mentionned values.
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(http://i.imgur.com/MuJl7aJ.jpg)
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Ok, thanks. And, why this reaction?
If I am missing something making my wonderings useless, could you explain it?
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Hi,
I am wondering about wiring choices, like using twisted wires or not, which wires...
Basically, one of the main issue is parasitic capacitance. Too much of it may reduce the pickups brightness.
Does anyone know what are the typical value for:
- the shunt capacitance of a BKP humbucker (or, better, one of its coils),
- the parastic shunt capacitances of a potentionemeter?
Using twisted wires may add parasitic capacitances up to 50pF in my case; and even when doing the math, I cannot say if it is bad without the previously mentionned values.
The main stray capacitance in your system is the guitar lead; the internal wiring pots etc will make an insignifcant contribution to stray capacitance.
The interaction between the pickup and stray capacitance is complex; the inductance of the pickup forms a resonant circuit with the stray capacitance which can cause peaking in the treble region ie more stray capacitance doesn't automatically mean less treble depending on the inductance of the pickup, the value of the stray capacitance and the series resistance.
The higher the series resistance the broader the peak. Series resistance increases as you turn the volume control down.
The input capacitance of your amp needs to be considered too, although in a valve amp there is often a largish resistor (typically 47-68k) isolating the guitar cable from the input stage capacitance (typically 100-150 pF). That is of course assuming you are not using pedals.
The interaction between the guitar pickups and stray cable capacitances is what "active" pickups are designed to eliminate.
Ultimately it's not something I'm overly worried about; assuming it's of decent quality, your guitar cable is not going to make the difference between a great sound and a shocking one.