Control pots working in reverse> HELP!

mark129

New member
I just installed 2 new duncans in my SG, "59 in the neck, Custom-5 in the bridge. The '59 has a single conductor wire, the C-5 a four conductor wire. I would like to wire these PU's so I can work them both independently in the middle 3 way switch position. I found a diagram in the Everything SG site, it was called "Wiring for dummies". I wired my pots the way the diagram said, and my controls work in reverse. When I turn my controls clockwise, my volume decreases, it should increase. On my old pots, the caps were soldered to the volumes left lug, to the tones middle lug. On this new diagram, the caps are soldered to the volumes middle lug, to the tones middle lug. Would this be my problem? I also get a loud hum when I turn my volumes up. I can't figure out why my controls work in reverse. I was also told on the 4 conductor wire to solder the white and green wires together, red as hot, black and bare as ground. Is this right? Can anyone help me out? These are not reverse left hand pots, I already checked.
 
Re: Control pots working in reverse> HELP!

mark129 said:
These are not reverse left hand pots, I already checked.

Heh-heh . . . there's no such thing as a "left-hand" pot. If you want a pot to work one way, you wire up its outside terminals one way. To reverse it, just switch the outside two terminals. Thats all you need to do to get them to work correctly.

On Duncan p'ups, generally, black is hot, green and braid are ground, and red & white get soldered together.
 
Re: Control pots working in reverse> HELP!

ArtieToo said:
Heh-heh . . . there's no such thing as a "left-hand" pot. If you want a pot to work one way, you wire up its outside terminals one way. To reverse it, just switch the outside two terminals. Thats all you need to do to get them to work correctly.

I thought that was only the case with linear taper pots, and that reversing wiring on an audio taper pot caused it to behave a little strangely?

(I could be completely wrong of course, I'm no electronics engineer I have to admit :biglaugh: )
 
Re: Control pots working in reverse> HELP!

southadc said:
I thought that was only the case with linear taper pots, and that reversing wiring on an audio taper pot caused it to behave a little strangely?

(I could be completely wrong of course, I'm no electronics engineer I have to admit :biglaugh: )

You are essentially correct. I just meant that its not called a "left-hand" pot. (Except, maybe in guitar slangiology.) If you want an audio-taper pot to go the "other" way, you'ld want to have a "reverse-taper" pot. I believe these are designated with an "N" or "M" suffix. (I'll have to check my catalog to be sure.) ;)
 
Re: Control pots working in reverse> HELP!

Mark; if that drawing is shown facing the back of the guitar, then its wired correct.
You're bridge pickup is not wired correctly, but that won't cause the problem you're having. The bridge should be:

Black to the center of the volume control.
red and white soldered together.
Green and braid to ground.

Double-check your wiring diagram and see if you copied it from the guitar correctly.
Also, which volume control works backwards, both, or just one?
 
Re: Control pots working in reverse> HELP!

Both volumes and tones work backwards. Someone told me if I just switch my wiring it would work fine. I don't know if they mean reverse the wires on the two outside lugs, or the first and middle lugs, and leave the third lug ground where it is? Yes, this diagram is looking down into the control cavity. I will change my 4 conductor wiring around, maybe thats why I'm getting a loud hum when I turn the volumes up. Does it matter which lugs I solder the caps to, as long as its not on the gound lug?
 
Re: Control pots working in reverse> HELP!

ArtieToo said:
Heh-heh . . . there's no such thing as a "left-hand" pot. If you want a pot to work one way, you wire up its outside terminals one way. To reverse it, just switch the outside two terminals. Thats all you need to do to get them to work correctly.

On Duncan p'ups, generally, black is hot, green and braid are ground, and red & white get soldered together.

Artie is the bare the shield for the pup wires? If so, wouldnt that eliminate the need to shield its cavities? Always wondered about that.
 
Re: Control pots working in reverse> HELP!

Mark; Yes, switching the outside two terminals will reverse the operation of the pot. In the case of the tone pots, it means the "other" terminal will be bare. But this also means that the drawing you posted can't be correct.

Picture this: You're looking at the back of the guitar. You place your thumb on the top of the volume control, and roll it towards the neck. (Towards the left, in your diagram.) That will short the wiper to the left terminal, which would be full volume. The tone is the same way. Rolling the top towards the left will put maximum resistance between it and the cap, which would be the tone control on "10".

I don't suppose you could post a pick of the front of the guitar could you? Showing the controls. Is it possible to have "left-hand" knobs? So that you're actually turning the controls the wrong way?

Just a thought.
 
Re: Control pots working in reverse> HELP!

Fritz6 said:
Artie is the bare the shield for the pup wires? If so, wouldnt that eliminate the need to shield its cavities? Always wondered about that.

Yes, it is the shield for the p'up wires, and also, usually grounds the pickup's mounting plate, but it doesn't necessarily eliminate the need to shield the cavities. I don't really have a lot of experience in this area. Hopefully someone else can comment on that aspect.
 
Re: Control pots working in reverse> HELP!

The knobs are right. I think I'll switch the ground to the fist lug and the 3 way switch lead to the third lug, where the gounds are now. I'll leave the PU lead on the middle lug with the cap and see how that works.
 
Re: Control pots working in reverse> HELP!

P.S. Does it matter which lugs the caps are soldered on to the volume and tone pots? Should I solder the cap on the volume pot with the PU lead wire, or with the 3 way switch wire? Then solder the cap to the middle lug on the tone pot?
 
Re: Control pots working in reverse> HELP!

Mark; before you do that, could you answer this? If you hold the guitar in your lap, and I assume you're right-handed, and you place your thumb on top of the volume control, and roll the top towards the neck, does the volume go up or down?
 
Re: Control pots working in reverse> HELP!

ArtieToo said:
You are essentially correct. I just meant that its not called a "left-hand" pot. (Except, maybe in guitar slangiology.) If you want an audio-taper pot to go the "other" way, you'ld want to have a "reverse-taper" pot. I believe these are designated with an "N" or "M" suffix. (I'll have to check my catalog to be sure.) ;)
Well, there is a *left hand or counter clockwise taper* which is a *right hand taper* ... *I* didn't name it that way so stop throwing stuff ... Apparently, it gets it's name from the fact that the log taper is tapered (or measured) from the counter clockwise lug,(which happens to be the lug on the left if you hold it with the shaft pointing up, and the lugs facing you) to the wiper, as the wiper travels clockwise (0~10) the resistance between the wiper and the counter clockwise lug increases according to a logarithmic, well ... increase in resistance. On a reverse *right hand or clockwise taper*, it's the same taper, but laid out from the other end, the measurement (tapering) is between the clockwise lug and wiper ... hence 0~10 travels in a clockwise fashion.So a left hand taper is for right handers, and a right hand taper is for left handers.
Like I said ... I didn't name it that way ... so stop throwing stuff ...
Bear in mind also that most tapers are approximations, and not exact log. tapers, I'm not talking tolerance, I'm talking the taper is slightly different... a quote *audio taper* can be just about anything that the manufacturer wants it to be... Just a side note. Some companies reverse there nomenclature, others use whatever taper code they seem to want. ... :smack:
 
Re: Control pots working in reverse> HELP!

mark129 said:
Both volumes and tones work backwards. Someone told me if I just switch my wiring it would work fine. I don't know if they mean reverse the wires on the two outside lugs, or the first and middle lugs, and leave the third lug ground where it is? Yes, this diagram is looking down into the control cavity. I will change my 4 conductor wiring around, maybe thats why I'm getting a loud hum when I turn the volumes up. Does it matter which lugs I solder the caps to, as long as its not on the gound lug?
The diagram looks just fine, except for that the bridge pup should be black hot, white and red together, and green to ground along with the shield/drain wire (assuming the neck pup is a duncan also, and not an Ant. Duncan). Just like Artie stated. I haven't a clue why the controls would be working backwards, that would seem to be a physical impossibility. :saeek:
 
Re: Control pots working in reverse> HELP!

ArtieToo said:
Yes, it is the shield for the p'up wires, and also, usually grounds the pickup's mounting plate, but it doesn't necessarily eliminate the need to shield the cavities. I don't really have a lot of experience in this area. Hopefully someone else can comment on that aspect.
The shield is to shield the wires coming out of the pup along it's cable and to provide a convient grounding to the baseplate itself. Generally with humbuckers you will not really notice any difference (depending on your enviroment) as the pieces of wire running between the controls a relatively short, and the pot cases themselves are grounded so they act as shields, the ground to switch bodies does somethimg similar (actually just keeps the control from humming when your finger touches it ... e.g. a DPDT switch).
It does not take the place of shielding the caivty itself ... However that doesn't mean that shielding the cavity is always necessary ...if your are playing right next to something putting out strong EMI/RFI emmissions, then yeah the shielding will help, without it, the non-shielded wires in the cavity might pick up the noise. With single coils though, shielding is pretty much a must, at least the pick guard ... but since singles pick up hum anyway, the only purpose of the shields are to minimize that. A strat with fully shielded interior, and pickguard; fully shielded covers (something not often seen due to mechanical/space issues), and proper grounding can go a long way towards making it hum free. So you need to have the pup baseplate grounded anyway,so the shielded cable is a good way to do it ... the choice to shield the cavity is a personal/ situational one.
 
Re: Control pots working in reverse> HELP!

Kent S. said:
Well, there is a *left hand or counter clockwise taper* which is a *right hand taper* ...

Now that you mention it, it does seem like I've heard that terminology before. ;)

Kent S. said:
I haven't a clue why the controls would be working backwards, that would seem to be a physical impossibility.

Yup, either Mark drew the diagram wrong, or, (and I may be way off base here), I wonder if maybe Mark simply put the knobs back on disoriented from there original position. In other words, the knob has "1" pointing up, when at full volume. It would be easy to miss that the numbers were rolling around the wrong direction.

Sorry Mark - don't mean to be talking about you in the third person in your own thread. :smack:
 
Re: Control pots working in reverse> HELP!

Ok guy's, I screwed up. It's a long story, but the pots are working right now. I also changed the wiring on the four wire conductor and tied the W/R together, green and bare wire ground, blk hot. Does it matter which lug on the volume and tone pots I solder my caps to? I'll get this right sooner or later :-)
 
Re: Control pots working in reverse> HELP!

mark129 said:
Ok guy's, I screwed up. It's a long story, but the pots are working right now. I also changed the wiring on the four wire conductor and tied the W/R together, green and bare wire ground, blk hot. Does it matter which lug on the volume and tone pots I solder my caps to? I'll get this right sooner or later :-)

It does, depending on what else you might want to do with the control, but for the run of the mill tone control (keeping with the LP style layout), you probably have the cap going to either the CW lug on the volume control (or the wiper), and then the other end on the cap going to the CCW lug of the tone pot, the wiper of that pot gets soldered to ground via the back of that pot. If you run the hook the pup side of the capacitor to the wiper of the volume pot instead of the CW lug; the guitar will lose less treble when the volume is turned down (aka ... '50's wiring). There are other ways to wire the controls as well, but we don't need to get into that, as they are specific to certain applications.
 
Re: Control pots working in reverse> HELP!

mark129 said:
Ok guy's, I screwed up. It's a long story, but the pots are working right now.

We all do! ;)

If its not too embarrassing a story, sometimes it helps others who might be having the same problem to post what went wrong. :)
 
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