Funky wiring for S/H combo

T

thechrisl

New member
Hey all, it's been a while since I last posted. I'm back working on a new project and wondered if I could get a sanity check on the wiring.

I'm trying to set up two pickups (1 Phat Cat and 1 humbucker) so they can be switched on and off individually, or both. I also added a switch to split the coils (upper or lower). Does it look like I'm on the right track with this?

I'm not sure if I'm correct with the Phat Cat since it is only a single conductor with a braided ground.

My other concern is when turning the volume down or all pickups=off. I don't want to cause any hum. My GTR does that today with the volume off, never could figure out why.

Thanks for any assistance.

gtrwiring.jpg
 
Re: Funky wiring for S/H combo

Something is definitely wrong with your wiring diagram but I am not sure what it is yet or how to resolve it.

For instance, the DPDT on/on switch for the Phat Cat. You have illustrated the HB output as connected to the lower middle lug on the switch.

When the internal contacts link the four lugs nearest the right side of the switch, the HB signal will be passed to the volume pot. When the internal contacts link the four lugs nearer the left side of the switch, the humbucker is isolated OUT of the circuit completely. As it stands, this switch will act as an either/or selector for your pickups. There will be no way to have both simultaneously.

Since the two pickups run in parallel and have independent on/off switching, the obvious thing to do is run independent output cables to the volume pot. The second alternative is to link the HB switch output to the TOP MIDDLE lug of the Phat Cat switch.
 
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Re: Funky wiring for S/H combo

I "borrowed" the ideas from a couple sources. The individual pickups portion came from this Brian May diagram (ignoring the phase switches):

brian_may_pickup_wiring_standard.gif


The versatile coil split came from Smits pickups (not sure why that switch is DPDT, looks like it could be SPDT).

coilta11.gif

coilta13.gif

coilta14.gif


I was trying to merge the two ideas but that's where my knowledge of circuits often gets cloudy...
 
Re: Funky wiring for S/H combo

The way you're wired you've got neck, bridge, or off, never both.

The Brian May wiring runs the pickups in series. Is this what you want?
 
Re: Funky wiring for S/H combo

Good point. I guess parallel would make more sense. Does this get me closer?

  • Individual off/on for each pickup.
  • Wired in parallel.
  • HB coil split (upper or lower or both)

gtrwiring2.jpg
 
Re: Funky wiring for S/H combo

OK, the more I think about this the more I think it may be impossible to have two pickups independently switchable (on/off) with only one volume/tone knob.

Part of my dilemma is that I have a thin body Ibanez and the only 3 or 5 way switches I can find are cheaply made and always scratchy (but fairly expensive!). I'm trying to get rid of it altogether and replace with a pair of small switches.

Hope I'm making sense here...
 
Re: Funky wiring for S/H combo

thechrisl said:
OK, the more I think about this the more I think it may be impossible to have two pickups independently switchable (on/off) with only one volume/tone knob.
Click to expand...
Nah, this is doable.

Part of my dilemma is that I have a thin body Ibanez and the only 3 or 5 way switches I can find are cheaply made and always scratchy (but fairly expensive!). I'm trying to get rid of it altogether and replace with a pair of small switches.
Hope I'm making sense here...
Click to expand...
Which Ibanez?
Are you talking about 3-way and 5-way blade switches?

If you have a blade switch that works(for simplicities sake a 3-way will suffice), you can add the series/parallel or coil split to that humbucker via a push/pull or push/push pot... you don't need to add extra switches. Add a 2nd PP pot and you can do phase as well.

The best 2-switch solution for your wiring scheme is a single on/off for the PhatCat and a single on/off/on for the humbucker.
Wire the on/off/on humubucker/off/split to whatever coil you prefer or parallel to keep humbucking.
This is how my late '80s Carvin DC135 was wired. 3 humbuckers, middle and neck were stacked single-sized, and 3 x on/off/on switches wired series/off/parallel.
Master volume, master tone.

This site might help.

You can also wire an on/on/on switch for a humbucker so that it does series/parallel/coil cut, which gives you the best of all worlds.
You'd need a 3 or 5 way switch, however.

And lastly, you can simply add a Seymour Duncan Triple Shot to your bridge pickup and then wire it normally to a 3 or 5 way switch.
This will give you series/parallel and coil cut, plus the ability to choose which coil is active.

If you want to add more versatility to your guitar, you can add 2 concentric pots, which will then give you volume and tone for each pickup, but you'd need something like the Triple Shot or an on/on/on to give you more bridge pickup options.

If you've got hum from your guitar, you've got grounding issues. Check your bridge ground and all your ground solder points. Also, you may have a ground loop issue.

I'll try to post some pics when I can get to it.

MM
 
Re: Funky wiring for S/H combo

thechrisl said:
I "borrowed" the ideas from a couple sources.
Click to expand...

I'm not surprised that things were getting confused.

Firstly, as somebody has already pointed out, the Brian May Red Special circuit runs the pickups in series. I once made my own variation on this circuit using just three DP3T switches.

The important detail in this variation was that the DP3T switches were of the on/on/on variety. It was the way in which the switch was wired that made the centre position off, NOT its internal contacts.

If you take another look at the official BM schematic, you will notice that all six DPDT switches are on/on. Again, it is the way that the terminals are interconnected that creates the 'off' position. This is because the "off" position is actually a hard-wired bypass.
 
Re: Funky wiring for S/H combo

thechrisl said:
OK, the more I think about this the more I think it may be impossible to have two pickups independently switchable (on/off) with only one volume/tone knob.
Click to expand...

Never heard of the Fender Mustang, Duo-Sonic, Jag-Stang et cetera?

thechrisl said:
Part of my dilemma is that I have a thin body Ibanez and the only 3 or 5 way switches I can find are cheaply made and always scratchy (but fairly expensive!).
Click to expand...

If your guitar is an Ibanez S series, you are stuck with the narrow eight-contacts-in-a-line selector switch dimensions. The classic CRL "Fender" type switch is not going to fit. On the other hand, some of the Schaller megaswitch designs might.

One of these ought to suit your requirements. http://www.stewmac.com/shop/Electronics,_pickups/Components:_Switches_and_knobs/Megaswitches.html
 
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Re: Funky wiring for S/H combo

Revised diagram works in parallel. There are a few unnecessary connections. You do not need to ground the terminals on the two on/on switches. The green wire on the humbucker can go straight to a ground or to the terminal as shown, which ever is easier. That terminal on the on/off/on still needs to be grounded.
 
Re: Funky wiring for S/H combo

Funkfingers said:
Never heard of the Fender Mustang, Duo-Sonic, Jag-Stang et cetera?

If your guitar is an Ibanez S series, you are stuck with the narrow eight-contacts-in-a-line selector switch dimensions. The classic CRL "Fender" type switch is not going to fit. On the other hand, some of the Schaller megaswitch designs might.
Click to expand...

I've heard of those Fender thangs but didn't know how they were wired.

Yep this is an S series so I am stuck with a limited range of electronics. I'm using a 3 way import today because I pulled the center pickup out. It "works" but is already starting to go bad (it's my 4th one). I think the micro switches are of better quality, cheaper and easier to work with. I'm not too worried about the appearance, this is more of a workhorse GTR now.

I have been using a concentric pot for the last couple years but it's not working out, ergonomics-wise, so I'm wanting to go back to individual knobs. Mainly so I have better control over the volume knob as I've been using it more lately.

I have looked at 1728 and think I will revise this again. And, having just recently discovered the Triple Shots, think I will be getting one of those as well (hopefully those tiny "nano" switches hold up over time!)

@MikeS -- Still trying to get my head around the kill switch thing but I read somewhere it's very important to short the hot wire to ground to prevent hum when the pickup is off. If both pickups are off and there is no path to ground (via the switches), isn't that a bad thing?

On a side note I am planning to rewire a Squier with the GFS Brian May pickguard. It's a lot of switches but visually they make total sense as to what does what. Despite appearances I always try not to go overboard with all these mods -- don't want end up stapling switch translation charts to all my straps! :boggled:

Thanks again for all the comments!
 
Re: Funky wiring for S/H combo

Ok, 4-way tele switch wired neck/both-series/both-parallel/bridge.
Push/pull volume pot wired to coil split or series/parallel the bridge 'bucker.
And you're done.

And dude, if you're going through switches like that, you're either using way too hot a soldering iron or you've got sledgehammer hands!
:)

I'd say invest in a good 4-way and a push/pull and be done with it.

MM
 
Re: Funky wiring for S/H combo

MojoMonster said:
Ok, 4-way tele switch wired neck/both-series/both-parallel/bridge.
Push/pull volume pot wired to coil split or series/parallel the bridge 'bucker.
And you're done.

And dude, if you're going through switches like that, you're either using way too hot a soldering iron or you've got sledgehammer hands!
:)

I'd say invest in a good 4-way and a push/pull and be done with it.

MM
Click to expand...

Great idea BUT the American switch is too wide to mount in the Ibanez S series control cavity. That front-mounted recessed jack socket requires a big chunk of wood to be left behind the cavity cover plate. Push-pull pots are problematic because of their height.
 
Re: Funky wiring for S/H combo

True on both counts!

I'm not punishing the import switches that much. They just tend to be cheaply made w/ poor contacts. The best one yet was the Ibanez OEM switch.

I'm looking into a pair of Triple Shots along with maybe 2 dpdt to get the job done.

Pondering what to put in the "Humbucker X" spot but that may be another thread...
 
Re: Funky wiring for S/H combo

thechrisl said:
@MikeS -- Still trying to get my head around the kill switch thing but I read somewhere it's very important to short the hot wire to ground to prevent hum when the pickup is off. If both pickups are off and there is no path to ground (via the switches), isn't that a bad thing?
Click to expand...

But the ground on your switches is only grounding the signal from the pickups and not doing anything to ground the output of the guitar. You're right that you don't want the hot output wire of the guitar left hanging open, but you still have the resistance of the volume pot grounding the output and preventing hum.
 
Re: Funky wiring for S/H combo

thechrisl said:
I'm not punishing the import switches that much. They just tend to be cheaply made w/ poor contacts.
Click to expand...

IMO, the heart of the problem is the slot through which Ibanez mounts the "import" lever switch.

On a Fender, the slot for the switch lever is between 2/ and 3/32nds of an inch. On the Ibanez S and some RG models, the slot in the wooden guitar top is more like 4/32nds. Plenty of room to allow mucho sideways waggling of the lever. On PCB-type switches THIS is what prises the wiper away from the contact tracks, leading to the crackling problems.
 
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Re: Funky wiring for S/H combo

drdave said:
But the ground on your switches is only grounding the signal from the pickups and not doing anything to ground the output of the guitar. You're right that you don't want the hot output wire of the guitar left hanging open, but you still have the resistance of the volume pot grounding the output and preventing hum.
Click to expand...

I prefer not to leave a coil hanging on the output side, but as far as leaving the output wire "hanging" on the ground side, it's exactly what happens with any typical pickup switch. Any RF static picked up by the coil is earthed.

thechrisl, you can leave the grounds in place if you like, I'm just saying they are unnecessary in this diagram. If you are going to have any noise it is going to be from the humbucker stud coil when the on/off/on switch is in the screw coil position.
 
Re: Funky wiring for S/H combo

Thanks guys. I agree that slot does allow too much play. Occasionally a particular position will just cut out altogether & require some wiggling. After over a decade of futzing with it (wow!), I'll give the micro switches a try.
 
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