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Offline Brooklyn_Bean

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Pickup splitting Hum
« on: December 07, 2018, 11:57:53 pm »
I have a quick question that, hopefully, someone can answer.
Imagine a 2-pickup guitar with a mini rail pickup, a cruiser, in the neck and a full sized humbucker in the bridge.

My question:
If I were to make the middle position of my 3-way switch operate the full neck pickup and the bridge humbucker spilt (so, only the bridge is split), would there be 60 cycle hum???

Thank you for any insight you can give me.

BB

Offline marcwormjim

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Re: Pickup splitting Hum
« Reply #1 on: December 08, 2018, 01:35:51 pm »
The 60hz radiation picked up by the bridge single coil would still be present, because there would not be a RWRP coil to cancel the noise.

You can achieve the sound you want by putting the bridge humbucker coils in parallel, then putting that signal in parallel with the series neck humbucker.

101: Any two single coil pickups of opposing magnetic polarity and wind direction will be hum-cancelling when combined in either series or parallel operation.

If you combine split humbuckers and find they’re out of phase, either swap the humbucker start and series-connection leads that are grounded when split to select the other coil, or reverse the wind of the desired coil by swapping the start and finish wires. This will entail rewiring the order of the two pairs of start and finish wires of the humbucker, in order to preserve both humcancelling and (potentially) its in-phase relationship with the other humbucker.

If they’re in-phase but producing 60-cycle hum, then flip the magnet of one pickup.

This strategy can be used to ensure that any desired combination of north or south coils between two pickups is humcancelling - It will only ever involve the changing of magnetic polarity and/or reversing the wind of the pickup via the start and finish wires, until you have the result you want.

This is why another theoretical solution would be an additional switch to add a humcancelling dummy coil between the split bridge humbucker and selector switch’s signal path.
« Last Edit: December 08, 2018, 01:43:25 pm by marcwormjim »

Offline Brooklyn_Bean

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Re: Pickup splitting Hum
« Reply #2 on: December 08, 2018, 02:28:40 pm »
Marcwormjim:
Thanks so much for the insight!

Offline Brooklyn_Bean

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Re: Pickup splitting Hum
« Reply #3 on: December 08, 2018, 03:16:47 pm »
So to achieve a hum-free sound I would have to split each pickup so only the outer coils were operating, giving a quieter telecaster type of sound.
Though I wonder how a split coil on a Cruiser would sound—probably pretty subdued.
« Last Edit: December 08, 2018, 03:21:30 pm by Brooklyn_Bean »

Offline marcwormjim

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Re: Pickup splitting Hu
« Reply #4 on: December 08, 2018, 11:28:29 pm »
A split cruiser would, in my opinion, be unusably weak. That pickup arguably only exists to replace a single coil with a mini-humbucker putting out a similar amount of voltage.

Food for thought: If you prefer the Cruiser’s level of output, but want a hum-cancelling split neck-bridge combo in the middle switch position that doesn’t have a huge drop in volume from the neck pickup, you could replace the Cruiser with a hotter pickup wired in parallel so that it ends up being similar in output to the Cruiser. I’ve found the Satch Track to sound nearly identical between parallel and split modes.

And yet another option is to keep the Cruiser and wire the switch to split only the bridge humbucker and put it in parallel with the Cruiser, but to wire a capacitor and/or resistor between the bridge humbucker’s series connection and ground. This, like parallel wiring, can yield a single coil-like tone from a humbucker that is still (largely) humcancelling. You may find having the Cruiser in parallel with a filtered bridge humbucker covers enough of the same ground as to be an agreeable compromise.

These are all things that can be experimented with.
« Last Edit: December 08, 2018, 11:36:45 pm by marcwormjim »

Offline Brooklyn_Bean

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Re: Pickup splitting Hum
« Reply #5 on: December 09, 2018, 07:15:03 am »
Your knowledge is enlightening and appreciated. Cheers!!!