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Adding coil splitters to a guitar with 1 volume / 1 tone pot

Posted: Thu Jan 08, 2009 4:28 am
by Armchair Bronco
I have a Squier Jagmaster and I've been thinking about upgrading the stock Duncan Designed pickups to some higher output GFS pups, maybe a PAF in the neck and a crunchy PAT in the bridge.

I'd like to add coil splitters, but is this possible (or smart) if my guitar only has 1 volume and 1 tone pot?

What are my options for either coil splitting/tapping or possibly installing a humbucker-sized P90 in the neck assuming that I only have one volume and one tone pot to work with, along with a 3-way switch?

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Posted: Thu Jan 08, 2009 4:39 am
by Armchair Bronco
By the way: I know I can do this with Push/Pull pots. But generally this is done on guitars where each pup has a dedicated volume and tone pot. My Jagmaster does not.

If I have, say, the neck pup split but not the bridge pup, how will this affect the shared volume & tone pots?

Posted: Thu Jan 08, 2009 4:39 am
by Haze
put a mini 3-way
http://guitarpartsresource.com/electric ... itches.htm
put it infront of your big 3-way
wire 1 coil to each end, middle goes to the big 3-way
you can do a bunch of different tones
14 last time i counted

Re: Adding coil splitters to a guitar with 1 volume / 1 tone

Posted: Thu Jan 08, 2009 4:50 am
by Nick
Armchair Bronco wrote:I have a Squier Jagmaster and I've been thinking about upgrading the stock Duncan Designed pickups to some higher output GFS pups, maybe a PAF in the neck and a crunchy PAT in the bridge.

I'd like to add coil splitters, but is this possible (or smart) if my guitar only has 1 volume and 1 tone pot?

What are my options for either coil splitting/tapping or possibly installing a humbucker-sized P90 in the neck assuming that I only have one volume and one tone pot to work with, along with a 3-way switch?

Image
How many pots you have don't matter. You can use a push/pull for either volume or tone pots, the only difference between the two functions of the pots is how they're wired and the tone pot having a capacitor on it. Basically all a push/pull is is just a regular pot on top with a switch attached to the bottom of it. The switch has nothing to do with the function of the pot. Consider them separate controls that are just piggybacked. So with your setup you can have neck pickup split on the volume pot, bridge pickup split on the tone. You can keep the 1 volume 1 tone setup just like you have it. Also you'll probably be wanting 500k pots if you haven't figured that out yet.

also, when you split the pickups usually you have a small volume drop, and of course they usually will sound brighter and thinner. You'll also have 60 cycle hum like you get with normal single coils. The big problem I've found with splitting pickups, is because manufacturers never really advertise samples of split pickups, you kind of have to just try them for yourself. Some buckers sound great split, some sound totally unusable (depending on your taste). Either way though, it's a cool way to add a new sound to a guitar.

Posted: Thu Jan 08, 2009 5:08 am
by Armchair Bronco
Someone on another forum suggested the following: put a HB-sized P90 in the neck, a hot 'n' crunch HB in the bridge along with a single push/pull pot for the HB and then have my tech add a new blend pot (like the ones used on the Jaguar Classic Player Special HH) to set the blend between the P90 and the HB.

If I get a zebra-finished HB, the upgrade would not only sound killer but LOOK KILLER as well!

Posted: Thu Jan 08, 2009 5:18 am
by Haze

Posted: Thu Jan 08, 2009 5:19 am
by Haze

Posted: Thu Jan 08, 2009 5:24 am
by Armchair Bronco
This looks like the ticket for the bridge, but it'd be nice to talk to someone who has actually tried out this pup as a split coil. I think the GFS Mean 90 is the way to go for the neck pup, but I'm not wedded to GFS for the bridge pickup. (Having said that, I don't want to put a $150 boutique pickup in a $250 Jagmaster, either.)

Posted: Thu Jan 08, 2009 5:26 am
by Haze
imo, split coils sound like ass, they have their own unique tone, but it's ass
just an opinion

Posted: Thu Jan 08, 2009 7:04 am
by Armchair Bronco
If I go P90/split HB, what kind of pots do I get? Two 500K pots, with one push/pull?

What about 2 P90s? If I do this, do I get two 250K pots?

Posted: Thu Jan 08, 2009 8:08 am
by Will
Armchair Bronco wrote:If I go P90/split HB, what kind of pots do I get? Two 500K pots, with one push/pull?

What about 2 P90s? If I do this, do I get two 250K pots?
Rule of thumb - take the DC resistance of the PUP times 45 and round to the nearest standard value.

For example, a standard single coil is 5.5kohms. Times 45 and you get 247.5k, which is closest to 250k.
A humbucker is around 10k, so you'd get 450k - closest to 500k.
P-90s can go either way IMO. You're looking at about 9k, which comes out to 405k. Going up to 500k is what most people would do, but you can also go down. 250k would be a bit too low, but there are 330k pots (which were standard on many vintage Gibsons).

Higher values will give a brighter, louder signal while a lower value will attenuate the highs slightly. The other important thing is taper. You want to make sure you get audio taper. Some people use linear taper for the tone control, but it tends to bunch up all of the tone variation in the last 1/4 of rotation.

I ramble too much, but 2 500k audio pots would work perfectly for both HBs and P-90s.

Posted: Thu Jan 08, 2009 9:56 am
by Armchair Bronco
DuoSonicBoy wrote:...Higher values will give a brighter, louder signal while a lower value will attenuate the highs slightly. The other important thing is taper. You want to make sure you get audio taper. Some people use linear taper for the tone control, but it tends to bunch up all of the tone variation in the last 1/4 of rotation.
Wow. It sounds like you've perfectly described the way *both* the volume and tone pots work on my new Fender Classic Player Jaguar Special HH. I've been complaining since Day One that I have to keep both pots basically dimed to make the pickups on this guitar come alive. As far as I can tell, the Classic Player Jaguar HH uses the same pot values as a conventional Jaguar, but because you're working with a combination of humbuckers and blend pots, there doesn't seem to be any taper at all.

I took this guitar into my tech earlier this week for its initial setup and I talked to him about this. He said the tone pot acted almost as if it was wired up backwards and the volume pot was basically only usable in the last 10% of its taper. Anything below 90% and the pickups became utterly lifeless. I've also heard anecdotally from other CP Jaguar HH owners similar descriptions of their pots.

Here's a link to Fender's schematics for this guitar that I posted on this site some months ago: link-o-ramma

The schematic seems to indicate that the tone and volume pots are 1 meg pots.

Given this, how do you think my CP Jaguar HH should be modded so that the volume & tone pots behave more like those on my Gibson SG Classic where the entire sweep of both pots is usable?

Posted: Thu Jan 08, 2009 10:21 am
by Mike
The master Volume and Tone pots already are Audio.

Posted: Thu Jan 08, 2009 11:59 am
by Nick
DuoSonicBoy wrote:
Rule of thumb - take the DC resistance of the PUP times 45 and round to the nearest standard value.

For example, a standard single coil is 5.5kohms. Times 45 and you get 247.5k, which is closest to 250k.
A humbucker is around 10k, so you'd get 450k - closest to 500k.
P-90s can go either way IMO. You're looking at about 9k, which comes out to 405k. Going up to 500k is what most people would do, but you can also go down. 250k would be a bit too low, but there are 330k pots (which were standard on many vintage Gibsons).
Pretty sure the old gibsons are 300k.

About that theory though, since you've got quite a few danelectros, if I'm not mistaken they use 1 meg volume pots and 100k tone. At least the concentric pots in the 90s reissues did. I know those lipsticks aren't anywhere close to 15k. Would you say it evens out because the 100k tone adds some darkness back in? Or is the tone pot irrelevant and is the 1meg just counteracting the dark natural sound of the lipstick?

Posted: Thu Jan 08, 2009 12:06 pm
by Mike
Nah, a 100k tone pot will make the pickups sound dark.

The same thing is done on the Rhythm Circuit of the Jazzy and Jag - 1meg vol and a 50k tone. It makes it sound way darker than the lead circuit which is 1meg, 1meg. I whacked a resistor in series with my tone pot on my Jag because I really don't like the dark rhythm sound, it's useless to me personally.

The problem with the HH jaguar is that the two Rhythm circuit pots are now coil split blends for the buckers, BUT they didn't change the values like idiots, so you have a 1meg blend for the neck pickup and a 50K blend for the bridge. I'm betting the bridge blending is arse as a result. I personally would use 500K or 1meg for both pickup blends, it is nonsensical (and lazy) to have them different.

Posted: Thu Jan 08, 2009 6:06 pm
by Will
Nick wrote:
DuoSonicBoy wrote:
Rule of thumb - take the DC resistance of the PUP times 45 and round to the nearest standard value.

For example, a standard single coil is 5.5kohms. Times 45 and you get 247.5k, which is closest to 250k.
A humbucker is around 10k, so you'd get 450k - closest to 500k.
P-90s can go either way IMO. You're looking at about 9k, which comes out to 405k. Going up to 500k is what most people would do, but you can also go down. 250k would be a bit too low, but there are 330k pots (which were standard on many vintage Gibsons).
Pretty sure the old gibsons are 300k.

About that theory though, since you've got quite a few danelectros, if I'm not mistaken they use 1 meg volume pots and 100k tone. At least the concentric pots in the 90s reissues did. I know those lipsticks aren't anywhere close to 15k. Would you say it evens out because the 100k tone adds some darkness back in? Or is the tone pot irrelevant and is the 1meg just counteracting the dark natural sound of the lipstick?
Ah, sit back young padawan and I will spin you the tale of Danelectro and their pots.
Nat Daniels used whatever he could buy in ridiculous bulk from other defunct companies. The unique Dano switch was overstock from an oven maker, the PUPs were lipstick tubes, and the pots were volume/balance controls from Buick (IIRC) radios. There was no science or design purpose for it, they were just cheap and worked. And, to be fair, they don't work as well as the "ideal" values. The volume control (balance on the radio) was 100k linear, so it didn't have a natural roll off and mostly just dulled the sound until the last 3rd of rotation. The tone (volume on the radio) was audio taper, but also 1M, way too high of a value. It doesn't start to roll off treble at all until about halfway down.
Most of the single PUP Danos used 1M for volume and tone, because this was the value Daniels was already using for his Fender Princeton and Deluxe style amps. Again, buying in bulk. Later, both pots became 100k, because this is what was used in the popular Cadet line of amps.
Daniels didn't think "tone", he thought "worked" - the Danelectro reissues just copied his original designs, probably without any regard to why the values were the way they were.
The "ideal" value thing is really based on the impedance of the PUP and is geared toward getting the most usable range of rotation without dead spots.

Posted: Fri Jan 09, 2009 12:03 am
by Mages
DuoSonicBoy wrote:Some people use linear taper for the tone control, but it tends to bunch up all of the tone variation in the last 1/4 of rotation.
really? because I've found the opposite to be true. audio pots tend to just dump on the whole capacitor on the last 1/4 turn. and if you graph out a logarithmic curve you can see how that would make sense.

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Posted: Fri Jan 09, 2009 12:40 am
by Nick
DuoSonicBoy wrote:
Nick wrote:
DuoSonicBoy wrote:
Rule of thumb - take the DC resistance of the PUP times 45 and round to the nearest standard value.

For example, a standard single coil is 5.5kohms. Times 45 and you get 247.5k, which is closest to 250k.
A humbucker is around 10k, so you'd get 450k - closest to 500k.
P-90s can go either way IMO. You're looking at about 9k, which comes out to 405k. Going up to 500k is what most people would do, but you can also go down. 250k would be a bit too low, but there are 330k pots (which were standard on many vintage Gibsons).
Pretty sure the old gibsons are 300k.

About that theory though, since you've got quite a few danelectros, if I'm not mistaken they use 1 meg volume pots and 100k tone. At least the concentric pots in the 90s reissues did. I know those lipsticks aren't anywhere close to 15k. Would you say it evens out because the 100k tone adds some darkness back in? Or is the tone pot irrelevant and is the 1meg just counteracting the dark natural sound of the lipstick?
Ah, sit back young padawan and I will spin you the tale of Danelectro and their pots.
Nat Daniels used whatever he could buy in ridiculous bulk from other defunct companies. The unique Dano switch was overstock from an oven maker, the PUPs were lipstick tubes, and the pots were volume/balance controls from Buick (IIRC) radios. There was no science or design purpose for it, they were just cheap and worked. And, to be fair, they don't work as well as the "ideal" values. The volume control (balance on the radio) was 100k linear, so it didn't have a natural roll off and mostly just dulled the sound until the last 3rd of rotation. The tone (volume on the radio) was audio taper, but also 1M, way too high of a value. It doesn't start to roll off treble at all until about halfway down.
Most of the single PUP Danos used 1M for volume and tone, because this was the value Daniels was already using for his Fender Princeton and Deluxe style amps. Again, buying in bulk. Later, both pots became 100k, because this is what was used in the popular Cadet line of amps.
Daniels didn't think "tone", he thought "worked" - the Danelectro reissues just copied his original designs, probably without any regard to why the values were the way they were.
The "ideal" value thing is really based on the impedance of the PUP and is geared toward getting the most usable range of rotation without dead spots.
I was talking more about the reissues more than anything, as I was almost certain they were 1meg volume 100k tone concentric.

So you mean to say in theory two 250k pots would sound better with a dano than the stock pots?

Posted: Fri Jan 09, 2009 1:11 am
by Fran
Drop some EMG 81'z in there dude.

Posted: Fri Jan 09, 2009 1:23 am
by Will
Nick wrote:So you mean to say in theory two 250k pots would sound better with a dano than the stock pots?
Sound is all subjective. I stuck 250ks in my '57 U1 and got a much more usable taper. The main problem I had was that the sweet spot on the tone control was very narrow and in the last quarter of rotation. A lower value spread it out and made it easier to tweak while playing.

It really isn't a question of sound or tone, more an ease of use question. 250ks in theory make for more meaningful and predictable rolloff across the entire rotation.

What really determines the range and effectiveness of the pot is the impedance of the pickup, which is very difficult to measure, so DC resistance is used as a substitute. There's still a little chaos at play, but the old standards were usually chosen for a balance of effectiveness while avoiding excessive loading.