Circuit diagram for coil splits, Phase and blower switch?

[amigarobbo]

I've got an old Epiphone Tony Iommi  Epiphone SG with 4 wires from each pickup, and I'm trying to upgrade the wiring to this functionality  :sad:

My google-foo skills are failing me, can anyone point the way to the circuit diagram?

Also I'd like to choose the hum bucking or coil tap that goes via the blow switch.

 

[line6man]

Splitting and tapping are two different things. I would assume that we are dealing with coil splitting, in this case? If so, what precisely should each switch do? Which coil should each pickup split to?

What is a "pure bypass" switch?

 

[Ace Flibble]

Coil split, not tap

The Coil splits and phase switch are easy. They're part of what's usually called Jimmy Page wiring, and you can find diagrams for that just about anywhere. Jimmy Page wiring usually includes a series/parallel switch, too, and you can just ignore that. The Seymour Duncan site also has wiring diagrams for two splits and a phase switch, as well, and it includes wire colour codes for most brands of pickup, so you can work out the diagrams even if you're not using Seymour Duncan pickups.

Now the bad news.

The bypass is not possible as you want it. You can't fit two pickups on one bypass switch and have the independent volume and tone controls. It takes all six contacts the switch has just to do one pickup, so each pickup would need its own bypass switch. The bypass has to come before the control pots, meaning it also comes before the pickup selector switch. It can't go after the toggle, because by that point the pickups have already gone through their pots; the bypass will have no effect.

If you had the bypass only affect one pickup, that could be made to work; simply complete the split and/or phase wiring for your chosen pickup, then send that signal to the bypass to be split off either toward the pickup selector toggle switch or the normal controls and then the pickup selector. That means you'd be giving up the option to choose which pickup was bypassing the control pots; regardless of where the pickup selector toggle is, only the one pickup would have the bypass in effect. You also wouldn't get the instant switching of a normal bypass switch; if you put the bypass on the neck pickup, but the pickup selector was on the bridge selection, you'd still be getting the normal bridge pickup when you activate the neck's bypass. You'd have to turn on the bypass and move the toggle switch to the right pickup.

If you reduced your control layout down to a single volume and tone then you could put the bypass after the toggle, and therefore you could still bypass the pots and could use the toggle switch to choose which pickup as normal. The chain then would be
pickups > split and/or phase switching > pickup selector toggle switch > bypass switch off > volume & tone > jack
or
pickups > split and/or phase switching > pickup selector toggle switch > bypass switch on > jack
You could still use the push-pull element of the other three controls as normal, but the actual normal volume and tone controls would be reduced down to a master volume and master tone; two of the pots would do nothing when you turn them. It would also mean that you'd be activating the bypass and then choosing your pickup, so it's a two-step procedure, again.

You could also give up one of the phase or split switches to create a second bypass. This way you could have a bypass for each pickup. So each pickup would go to its split or phase switch—whichever you chose to keep—and then the bypass, which would send the signal either straight to the toggle, or through the volume and tone controls for that pickup and then to the toggle. Like before, this would create a two-step activation, where you would turn on the bypass for the pickup you want, and then also have to switch the pickup selector toggle to the right position.

The last option to make this work is to add additional switches for the bypasses. You could do this by drilling another hole or two in the guitar to install another pot or on/on mini-toggle switches, or buy some Seymour Duncan Triple Shot mounting rings—measure your existing rings carefully to make sure they match—which take care of the splitting for you, so then you could make the volume controls into bypasses, instead.

... So it's all a lot of work and there's no way to make it work exactly how you want with all the controls included. Have a think about what your priority is—independant controls for each pickup, splitting, phase switching, or a bypass—and ditch whichever element you're least interested in, or think about reworking the control layout to move some options away from the push-pull pots and onto additional on/on switches or triple shot rings.

And no, there's no diagram for any of this! What you're asking for is very, very unusual. (And, as explained, not really possible without making  few changes to the control scheme.) Again, the Seymour Duncan site and blog have diagrams and posts explaining every kind of switching you can name, but not in this configuration all at once, so what you're going to have to do is look up a bunch of them and combine several diagrams into your own.

 

[stratamania]

If by a blower switch you mean one that takes one humbucking pickup such as the bridge pickup and bypasses all other circuitry direct to the output Jack have a read.

https://stratamania.wordpress.com/2014/12/03/4pdt-blower-switch-for-guitar/

The challenge you would then have is what type of switch to use. There aren't that many available that will do the job.

 

[Timmsie95]

If by a blower switch you mean one that takes one humbucking pickup such as the bridge pickup and bypasses all other circuitry direct to the output Jack have a read.

https://stratamania.wordpress.com/2014/12/03/4pdt-blower-switch-for-guitar/

The challenge you would then have is what type of switch to use. There aren't that many available that will do the job.

wow, I was consitering one of these in one of my guitars, but now i'm not so sure, unless i had someone else do it  :laughing7:

 

[Timmsie95]

actually just found this, and it uses a normall dpdt switch, from wha I can tell
http://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-adding-a-blower-switch

 

[amigarobbo]

Coil split, not tap

The Coil splits and phase switch are easy. They're part of what's usually called Jimmy Page wiring, and you can find diagrams for that just about anywhere. Jimmy Page wiring usually includes a series/parallel switch, too, and you can just ignore that. The Seymour Duncan site also has wiring diagrams for two splits and a phase switch, as well, and it includes wire colour codes for most brands of pickup, so you can work out the diagrams even if you're not using Seymour Duncan pickups.

Now the bad news.

The bypass is not possible as you want it. You can't fit two pickups on one bypass switch and have the independent volume and tone controls.

1: Apparently the new Gibson pickups 'coil taps' are that, i.e. when activated still humbucking but less coils so not so loud or warm. On my Tony Iommi they will of course be coil splits.

(I also had to read trough that twice to make sure I used 'split' and 'tap' in the right place..)

2: The blower switch (is there a better term for it? Pure Bypass? output straight from the pickup to the jack, no volume, no tone, no nothing) is for the Bridge pickup only.

Also reading the Gibson page it seems they change the Neck pickup with phase control that seems to be a good idea, as I could see it could be possible to turn the guitar off if the bridge pickup is used for the phasing.

So, I'm thinking http://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-adding-a-blower-switch on the bridge tone DPDT switch, then going to the volume with a coil (s)tap(/s) spliter which should still work with the blower switch as the second coil will be earthed out of the circuit.

I'll have a think about the phasing...

It's doing me head in!

 

[amigarobbo]

And no, there's no diagram for any of this! What you're asking for is very, very unusual.

It's standard Gibson wiring.  :evil4:

 

[Logrinn]

actually just found this, and it uses a normall dpdt switch, from wha I can tell
http://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-adding-a-blower-switch

But that wiring doesn't take into account if you want to do coil split och series/parallell wiring on the humbucker as well, the way Stratamanias wiring does.

 

[Timmsie95]

You can still use coil tap/split with that wring. It would be a completely different section of your wiring.

actually just found this, and it uses a normall dpdt switch, from wha I can tell
http://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-adding-a-blower-switch

But that wiring doesn't take into account if you want to do coil split och series/parallell wiring on the humbucker as well, the way Stratamanias wiring does.

 

[Timmsie95]

You can also use individual taps just by sending the wire from the pickups to individual switches, rather than both pickups to one switch.

 

[Logrinn]

But when you in that case engage the "blower" switch you would still have a connection to other parts of the wiring through the coil split wiring - meaning this part of the pickup isn't bypassed -, with the risk of getting undesired results. If that coil split is connected to another coil on another pickup through a 5-way switch for instance, it would mean you are sending part of the signal to another pickup. And even if that pickup isn't connected to the output at the moment, will it yield unwanted result by adding to the load/impedence/resistance/something of the pickup you are trying to get the full blast out of?

 

[amigarobbo]

actually just found this, and it uses a normall dpdt switch, from wha I can tell
http://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-adding-a-blower-switch

But that wiring doesn't take into account if you want to do coil split och series/parallell wiring on the humbucker as well, the way Stratamanias wiring does.

I think I've worked out the blower section, anyone want to see my 'back of a fag packet' diagram?

Which should give you some idea of the kind of mind you're dealing with here!

 

[stratamania]

If by a blower switch you mean one that takes one humbucking pickup such as the bridge pickup and bypasses all other circuitry direct to the output Jack have a read.

https://stratamania.wordpress.com/2014/12/03/4pdt-blower-switch-for-guitar/

The challenge you would then have is what type of switch to use. There aren't that many available that will do the job.

wow, I was consitering one of these in one of my guitars, but now i'm not so sure, unless i had someone else do it  :laughing7:

Wiring an S1 switch takes a bit of doing even if you use a simpler switching. It can be a bit fiddly. I have one in a Tele for a different scheme and also there wasn't a lot of space to play with.

 

[stratamania]

The only way you can send a 4 wire Bridge Humbucker bypassing all other controls and selector switches completely cleanly is via a 4PDT as in my blog link.

Doing it any other way if you want to retain the ability to split the coils when it is in circuit will result in a less than clean switch. Without four poles you will get part of the circuit connected whether the blower is engaged or not. You'll see this elsewhere referred to as bleed.

Suhr also use a 4PDT for blower switches but they have a specially made five way with a push push button switch and circuit board mounted to it. They also have a laser to cut the hole in the body for the switch. If you search various other forums John Suhr, himself stated that you need the 4PDT.

I don't have a laser or access to Suhr's switches so I drew up the diagrams and ideas on my blog link.


Edit, I forgot to add that a lot of modern Gibsons have small circuit boards inside not just 4 pots, so unless you have one to reverse engineer there could be more going on than meets the eye.

 

[Ace Flibble]

And no, there's no diagram for any of this! What you're asking for is very, very unusual.

It's standard Gibson wiring.  :evil4:

There's nothing standard about individual splits, a phase switch and a bypass :laughing7:
And the 'tapping' on the Gibsons which you speak of is not tapping. It is splitting, and you do get hum. They just happen to have less hum than a normal split because Gibson have vastly improved the internal shielding and grounding of all their pickups and PCB boards.
This is a common misunderstanding caused by Gibson's confusing marketing, which they were pretty much forced into because everybody gets tapping and splitting mixed up. I've literally talked to their UK PR team about this for a couple of hours while we sat in their London offices trying to work out how the hell to explain things to people properly.

Anyhoo, to answer the points you bring up:
Yes, it's better to just call it a bypass. The phrasing 'blower switch' is incredibly uncommon and very dated.
Your original post indicated you wanted to be able to choose what's going via the bypass. That is what causes the problmes. If you actually don't want that and you do just want the bridge pickup to go via bypass, that's very easy.

Wire the splits and phase switches as normal. Then, instead of sending the pickup signal from those switches to the volume pot, have them go to the bypass switch. From there you have one wire carrying on to the volume pot, and one to the jack. So the split/phasing comes before the bypass, and the pots and toggle come after the bypass.

Doing this does mean that if you have the toggle switch in the middle or neck position, and you activate the bypass, you'll get the bypassed bridge sound on top of the neck pickup signal. You'll only get the plain bridge signal if you set the toggle switch to the bridge position.

To make it so the bypass also ignores the toggle switch, you will need to wire the toggle to the bypass. Where you'd normally wire through the pots, to the bypass and then on to the toggle, intead you'd wire to the pots, to the toggle, and then have the hot from the toggle return to the bypass.
So the bridge pickup goes to the split and then to the bypass. The 'off' part of the bypass goes to the volume and tone pots, and then to the toggle. The neck pickup goes to the split and the phase switch, and then the volume and tone pots, and then the toggle. The toggle's output then comes back to the bypass.

This will mean turning the bypass on will give you only the bridge output, and only the bridge split will be able to do anything; the volume and tone controls, and the whole neck pickup, won't give any signal.
The downside is you may indeed get some noticable bleedover. With a 4-pole switch you could negate the toggle switch more cleanly, but with the 3-pole you have with a push-pull, I have a feeling you'd find the volume and tone controls would have a slight effect on the pickups they're not meant to effect. This is very much an in theory wiring scheme, 'cause I've never heard of anybody trying this specific combination of switches all at once, so you may find it works perfectly, or it might have such horrific bleedover that you basically have to treat all the volume and tone controls as master controls. I've installed all these elements in guitars before, but all of them at once is something new.

I'll hack together a full schematic tomorrow, I've not quite got the time right at the moment.

 

[stratamania]

Ace, I'd be interested to see what you come up with.

Sure you could rig something up with various bits and get crosstalk or bleed but that's working to the limitation of a push pull pot. Either the entire circuit is bypassed cleanly or it isn't. Unless someone knows of one with a 4PDT attached.

I notice Fender on the new Elite is using an S1 in the HSS Stratocaster model to send the bridge via a "passing lane".  I'd be interested to see what wiring they are using. Perhaps they looked at my blog...but either way the S1 is a very flexible switch. Not sure if a strat or Tele knob on an LP would look any good...

As with all thing wiring wise, what seems like a good idea may turn out to not get much use in practice.

 

[Ace Flibble]

Well I think I've done it. I think.

Once again, I've left this way too late in the day (it's actually 1:06am here), but I said I'd do it so here's a scrappy attempt at illustrating how it could be wired. I don't typically use diagrams myself, as I just wire everything off the top of my head/by heart, so I do not pretend to be an expert at drawing these things. I thought I keyed out enough colours to handle everything, but it turns out I didn't. Balls.

I've used Seymour Duncan colours, as they're what I've installed most often. The SD site has a handy guide to how all the pickup wire colours translate between manufacturers, and I've put in a key and labels to hopefully better explain my shoddy drawing.

Both pickups can be split, neck pickup can have the phase changed, and the bypass should send the bridge straight to the jack, ignoring everything else.

I've probably overlooked something really basic, but for someone with a severe head cold, crippling nerve pain and awake at 1am, I think this should work.

... I fully expect at least four people to each point out at least five things that are wrong with this.

 

[Timmsie95]

Well I think I've done it. I think.

Once again, I've left this way too late in the day (it's actually 1:06am here), but I said I'd do it so here's a scrappy attempt at illustrating how it could be wired. I don't typically use diagrams myself, as I just wire everything off the top of my head/by heart, so I do not pretend to be an expert at drawing these things. I thought I keyed out enough colours to handle everything, but it turns out I didn't. Balls.

I've used Seymour Duncan colours, as they're what I've installed most often. The SD site has a handy guide to how all the pickup wire colours translate between manufacturers, and I've put in a key and labels to hopefully better explain my shoddy drawing.

Both pickups can be split, neck pickup can have the phase changed, and the bypass should send the bridge straight to the jack, ignoring everything else.

I've probably overlooked something really basic, but for someone with a severe head cold, crippling nerve pain and awake at 1am, I think this should work.

... I fully expect at least four people to each point out at least five things that are wrong with this.

from what I can tell, you've done it. haha. took me a while to follow everything, but i think that would work.
with that much wiring though, your true pickup's tone would probably be diminished.

 

[stratamania]

Ace, thanks for putting the diagram together. Makes it easier to see what you were describing.

If I am interpreting it correctly...

Where the bypass on the hot wire of the bridge on the switch on the back of the tone pot bypasses the hot wire to the jack or the rest of the circuit, I would think even when bypassed the red and white wire on the switch on the back of the bridge volume pot is still in circuit.

So if the bridge was split or not via the volume pot push pull, that would be still the case when the bypass on the back of the tone pot was used. So you would get either a full humbucker sent to the output Jack or the split signal. Not sure if it would create noise, I suppose the thing would be to try it.

I guess we then get to what is the definition of a "blower" switch, or its intended use. If someone is happy to bypass most of the circuitry apart from the split or whether they want to bypass all circuitry.