Jump to content

Hum cancelling question on a strat with HSS setup where the singles are noiseless.


Bubee

Recommended Posts

  • Members

I have a strat equipped with Fender not noiseless pickups. I am considering changing out the bridge pickup with a traditional two-coil humbucker. (I realize that the other two pickups are technically humbuckers, but with the stacked coil design they look like old fashioned single coils. Plus the two coil humbucker would be splittable, while the hot noiseless are not.) I worked out a wiring schematic using a 5-way super switch. My positions, from neck to bridge, will be: 1. Neck only 2. All three pickups in parallel (bridge pickup using only outer coil of the HB) 3. Middle only 4. Neck and bridge in parallel (again, bridge pickup using the outer HB coil only) 5. Full bridge humbucker........so....... My question concerns positions 2 and four: Would it still be hum cancelling? (Mixing a stacked humbucker with a single coil of another HB, in parallel with each other.)

Link to comment
Share on other sites

  • Members

The key there is equal and opposite completely nulls hum. Inductors buck hum by resisting change in voltages. If one coil is stronger then another or you have less phase cancellation of the ac hum. If you have for example two north coils vs one south coil you may only have a 50% drop in hum.

 

There are ways around that however. If you have a single coil and don't plan on reversing it, simply rewire the pickup with a shielded cable instead of two single leads. You can also use dual core shielded wire if you want to do series or reverse polarity windings.

 

you also have the option of shielding the pickguard and cavity with copper foil to act as a faraday box to keep hum out. The only thing that remains exposed at that point may be the pickups themselves. I've used grounded copper foil tape inside plastic covers and it does wonders blocking hum.

 

You need to remember, Fender type guitars were originally designed as low budget mass produced guitars. They didn't shield anything very well. They used unshielded wiring, unshielded pickups and exposed wiring to the controls. You didn't hear much hum from them because they were used with clean low gain amps so the noise floor was very low compared to the actual string tones. Hum didn't become a problem till they gained up amps and started using fuzz pedals which brought the noise floor way up where you could hear it through an amp.

 

Gibson did a much better job shielding leads with their braded wire, Still do. Fender has stuck with their cheap construction even though the methods of combatting hum have been well established. Their primitive wiring has been institutionalized for some stupid reason as being Vintage. Hells Bells man, using shielded wire to the pickups doesn't change the tone of the instrument at all. In fact with a lower noise floor the instruments is actually helped by the increased dynamic range.

 

They know this of course but the general public doesn't. The guitars they did use it on didn't have improved sales and may have even been bashed by some as being non traditional. What I say is screw tradition. No one is going to know what's under that pickguard besides me. When I have hum, I eliminate it using any and all methods. I even have some conductive shielding paint I've used on a couple of guitars to get rid of stray hum. I used to have to do overkill on that when I used CRT monitors in the studio because they emitted a high level of 120hz hum.

 

In your case, I'd likely dump the 5 way switch however. I'd install mini toggels. you have a bunch of cool ways to wire them. With on/off/on toggels you can wire humbuckers series/off/parallel You can do coil tapping too for getting traditional fender tones too.

 

I've done this many times by removing the 5 way and drilling three holes in its place, then use a cover plate over it to make it look nice. Its allot easier getting to toggels too.

 

Another method I used on my last guitar mod is to keep the 5 way working normal, then just install push/push pots (you can use push pull pots too but trying to pull a pot up when playing doesn't work for me. The Push/Push work like a ball point pen. They don't stock up as high when engaged either.

 

With three knobs, and a 5 way you can nail just about any wiring config you can think of. In my last build I installed three mini humbuckers in a strat. I use two of the Push/Push knobs for coil tapping and the third for getting the bridge and neck together.

 

I'm likely going to revamp that decision however. I may try using the switched pots for series/parallel and use the two tone control pots to coil tap. I like using the pots to coil tape because they gradually tap instead of being a hard switch. I never use tone controls anyway so I actually get some use from those pots.

Link to comment
Share on other sites

  • Members

You will get noise in positions 2 and 4.

 

Instead of using just one coil of your HB pickup you could wire the coils in parallel. This will give you close to a single coil sound but without the noise.

 

Is your 5-way superswitch a four pole five position switch with 5 seperate lugs for each pole?

Link to comment
Share on other sites

  • Members

Inductors resist a change in Current not Voltage. It's Capacitors that resist the change in Voltage.

 

Inductors, by themselves, do not buck hum. The current introduced into coils wound in opposite directions will also travel in opposite directions which is why, under certain conditions, two inductors connected together can cancel out inductive noise (or buck the hum).

Link to comment
Share on other sites

  • 4 months later...

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...