slowburnaz
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Basses with dummy coils …
- Thread starter Green Knight
- Start date
edwinhurwitz
Supporting Member
No. The hum canceler has its own separate preamp channel which can be blended into the other pickups. This sets them apart from many of the other dummy coil designs. In my view, it's essential.
A pickup has resistance, capacitance, and inductance. A dummy coil, if it's going to be used to cancel hum, is going to have similar characteristics to the pickup it's used with. If wired in series, there will be more inductance. It's difficult (in most cases, practically impossible) to make that sound the same as the pickup itself. If the dummy coil is similar enough in impedance, you can wire them in parallel, which will halve the impedance. In that case, you can capacitively load the combination, and get back to the same sound that you had with just the pickup - in that case, you will trade away some level to do that.
I seem to recall that Xotic has a dummy coil system, which they call HRI (Hum Reduction Inductor).
Dumb question, is this basically the same idea as a p bass split coil pickup? Leo fender just offset the 2 halves but could have had it look similar to the single coil p bass? Probably a smart marketing thing to differentiate
A notch filter tuned to 60 Hz will do very little to get rid of most hum situations. Hum is from fields that escape things like transformers - the mechanisms usually emit mostly harmonics of 60 Hz, not 60 Hz itself.
That is a good way to do it, but it is not entirely without side effects. In the case of parallel active circuits, what you lose is a bit of signal to noise - the hiss level will be a bit higher. Practically speaking, the reduction in hum is far more helpful that the extra hiss is harmful.
All hum cancelling schemes are very similar in the basics of how they cancel hum - 2 coils, each one pickups up the same noise, but with opposite polarity. In other respects, they can differ - the typical humbucker arrangement where each string is llstened to by both coils has comb filtering from the spacing between coils that notches high mids (the frequency of the dip is different on every string). The split P (and similar pickups), the dummy coil approach, sidewinders, in line hum cancellers, and stacks all avoid this high mid dip by only listening to each string at one point.
Some types of noise that single coils pick up can be reduced or eliminated by using a metal pickguard that fully surrounds the pickup. It doesn't help with basic hum though. In my experience (to my ears) it has no impact on tone.
Noiseless = a hum cancelling pickup that Marketing renamed.
There are 2 kinds of noises you get from the environment - electrostatic noise (often buzz) and magnetic hum. Shielding helps (often quite well) with electrostatic interference, but won't help magnetic hum one bit. Hum cancellation is the cure for magnetic hum. If you want a quiet bass, it needs hum canceling pickups and good shielding. Not one or the other, both.
Dummy here: If simple copper-wound Siamese twin single coils cancel-out hum, how do they not cancel out ALL of the sound? What am I missing?
It's kinda like the XLR cable thing, right? ( again, see first word of this post )
It's kinda like the XLR cable thing, right? ( again, see first word of this post )
As far as I know, yes, same idea as splitting the P pup. There isn't any kind of magic voodoo going on, just split the pup in two, wire it up as one going through the route to the controls.
IMHO, the best use of a dummy coil is Ibanez's ATK triple bucker. I explain it in this video.
