What tone pot lug do I solder the cap to? ... Not a newbie question!

[Tony_H]

Hi folks,
here's the deal: I had this Les Paul Studio that had the tone control caps soldered to the central tone pot lugs, and the lower pot lugs (as seen from the rear when the guitar is in playing position) were soldered to the back of the pots. The other 'leg' of the cap was soldered to the same vol pot lug as the pickup hot lead.

This setup worked great - the tone controls would soften the treble without killing detail in the tone, and (to my ears) one pickup's tone pot did not affect the other pickup's tone. The blended tone with both pickups on retained clarity while being round and, well, 'plush-y' (sorry for the word).

I want to get this setup with a guitar that only has one volume pot. I tried to do it like this: The pup hot wires are connected to their toggle switch lugs. The tone pot caps are soldered to the switch lugs on one end and to their respective tone pots' central lugs on the other end. The tone pots' lower lugs (viewed from rear with guitar in playing position) are soldered to the backs of the pots.

I am using a large Gotoh 500K audio pot for the neck pup tone control and a small push-pull Stewmac 500K audio pot for the bridge pup tone control and to split both pups.

What happens is that there is little tonal change throughout most of the pots' rotation, then at the end the highs get quickly sucked out. Plus, when using both pups, no matter what tone control I turn, I end up with uniformly muddy, indistinct tone.

What's the problem? I have a couple ideas but am not sure which one is right.

1. The obvious: I need a second volume control for this setup to work. That's something I don't want to do in the first place - I like having just one global volume control, plus the guitar was custom made to my specs and this mod would require some routing, which I'm reluctant to do.

2. It's the tone pot wiring: I know there is an other way to wire the controls: a lead from the pickup (vol pot lug) to the tone pot's lower lug, and the cap is soldered to the central lug with one leg and to the pot back with the other leg. Will this help?

I don't think the problem is in the pots themselves - they certainly are audio taper and the quality has been good since I've been using them.

Can you suggest anything?
Thanks
Tony

 

[Lewguitar]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

You only have three controls? One master volume and two tone controls?

Connect each pickup to your selector switch and connect each pickup's tone pot to the same terminal on the switch that the pickup is connected to.

Then connect the output of the switch to your volume control and the output of the volume control (the middle terminal) to the output jack.

Lew

 

[Artie]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

I don't think thats going to work. In a normal twin-volume/twin-tone control guitar, the volume pots act as the "isolation" between tone controls. You don't have that. Doing what you are doing will give you independent tone controls only when you have one pup selected.

When both pups are selected, you have one tone control, with two handles. And its electrical value will be this:

The two 500k pots will be seen as one 250k pot.
The two cap values add together the same way. So if you're using two .022uf's, they'll be seen as one big .044uf. You'll definitely have a tone-sucker on your hands.

You really can't do twin tones, with one volume control.

Edit: Just thought I'd add, you could always use a dual-concentric pot for the volume control, so you wouldn't have to drill holes.

 

[Lewguitar]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

I don't think thats going to work. In a normal twin-volume/twin-tone control guitar, the volume pots act as the "isolation" between tone controls. You don't have that. Doing what you are doing will give you independent tone controls only when you have one pup selected.

When both pups are selected, you have one tone control, with two handles. And its electrical value will be this:

The two 500k pots will be seen as one 250k pot.
The two cap values add together the same way. So if you're using two .022uf's, they'll be seen as one big .044uf. You'll definitely have a tone-sucker on your hands.

You really can't do twin tones, with one volume control.

I think what I described would work Artie. It's really no differant than a Les Paul's normal wiring minus the two volume controls. Yes...when the two pickups are combined the two tone controls will be interactive, but that's just like they are on any Les Paul.

When the two pickups are used individually the two tone controls will not be interactive with the method I described because they will be isolated by the switch. Just as they would be in any Les Paul.

And I can't see any issues with connecting the single volume control to the output of the switch and then the output of the volume control to the output jack.

Lew

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

You only have three controls? One master volume and two tone controls?

Connect each pickup to your selector switch and connect each pickup's tone pot to the same terminal on the switch that the pickup is connected to.

Then connect the output of the switch to your volume control and the output of the volume control (the middle terminal) to the output jack.

Lew

Thanks but that's not the problem part of my post. My question was more like this: connecting the tone pots to the respective switch lugs, do I:

a) solder one end of the capacitor to the pup selector and the other end of the cap to the pot's middle lug, with the pot's lower lug soldered to the pot casing, like this: http://www.seymourduncan.com/website/support/schematics/humb.html (I know the schematics is for 2 vol pots, but I'm after the tone pot wiring so pls take note of the positioning and wiring of the tone post and disregard the rest)

or

b) solder one end of the cap to the pot's middle lug and the other to the pot casing, and solder the wire from the switch to the tone pot's top lug, similar to this (again, pls pay attention to the tone pots only, that's what I'm most concerned about).
http://www.seymourduncan.com/website/support/schematics/2hb_1vol_2tones_3way.html

I know there was a discussion on the two ways of wiring the tone pups but cannot find it.

Sorry, it's lengthy and perhaps not very clear...
Tony

 

[Lewguitar]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

I'd wire the tone pots the way you described.

I'd connect the middle terminal (the wiper) of each pickup's tone pot to the same terminal on the switch that the pickup would be connected to.

Then I'd connect a .02 cap between ground and the other tone pot terminal.
You could solder one end of the cap to the back of the pot.

The remaining unused terminal on the tone pot could be clipped off.

 

[Artie]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

What you're saying is true, but the two tone controls still add together as I said, even on an LP. Just as an example, Tony didn't say what value caps he's using, but lets suppose he's using a .022uf for the neck pup, and a .01uf for the bridge, (with his 500k's).

When you select neck and bridge together, electrically, the tones will be seen as one .032uf cap fed through one 250k pot. You'll have two knobs, but both knobs will affect both pups.

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

I'm starting to realize I'm mixing up two problems:

1. Can a one volume, two tone, two humbucker guitar act like with dual volume controls (as I described above)?

2. Is there a tonal and operational difference between the two ways of wiring the capacitors to the tone controls as per the two links in my previous post? I believe there is...

... adding even more confusion...

Thanks
Tony

 

[Lewguitar]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

What you're saying is true, but the two tone controls still add together as I said, even on an LP. Just as an example, Tony didn't say what value caps he's using, but lets suppose he's using a .022uf for the neck pup, and a .01uf for the bridge, (with his 500k's).

When you select neck and bridge together, electrically, the tones will be seen as one .032uf cap fed through one 250k pot. You'll have two knobs, but both knobs will affect both pups.

Maybe so...but that's still the way all Les Pauls are. The interaction exists when the pickups are combined but that interaction has not really been a problem and it's the way all Les Pauls, SG's, 335's, etc. have been wired for the last 50 years. Lew

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

What you're saying is true, but the two tone controls still add together as I said, even on an LP. Just as an example, Tony didn't say what value caps he's using, but lets suppose he's using a .022uf for the neck pup, and a .01uf for the bridge, (with his 500k's).

When you select neck and bridge together, electrically, the tones will be seen as one .032uf cap fed through one 250k pot. You'll have two knobs, but both knobs will affect both pups.

I'm using two 47 microfarad caps ... so if they add up like you say, there will be a huge treble cut won't there?

At least I know it can't work the way I want it to without dual volume pots. The concentric pot thingy seems the way to go here...

Thank you Artie
Thank you Lew
Guys I'm gonna watch your conversation because you're really helping me now.
Tony

 

[Artie]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

I'm using two 47 microfarad caps ... so if they add up like you say, there will be a huge treble cut won't there?

At least I know it can't work the way I want it to without dual volume pots. The concentric pot thingy seems the way to go here...

Thank you Artie
Thank you Lew
Guys I'm gonna watch your conversation because you're really helping me now.
Tony

Just to be clear, what Lew is saying is absolutely correct. Its the way that all dual-volume/dual-tone control guitars are wired. I just wanted to make sure you understood that it won't be like you can roll all the treble off one pup, and leave the other "bright". It won't work like that.

Edit: Only when both pups are selected.

 

[Lewguitar]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

Thanks Artie and Tony. This one's settled....right? :laugh2:

 

[Artie]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

This one's settled....right? :laugh2:

Yes . . . :laugh2:

Sometimes I wonder if I'm not making matters fuzzier, rather than clearer, by my hang-up with the dual-volume/dual-tone thang! :blackeye:

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

Just to round it off:

I wired my guitar like this:

http://www.seymourduncan.com/website/support/schematics/2hb_1vol_2tones_3way.html

No pup splitting - just two good ol' CTS 500K A pots, two humbuckers.
I'm now considering the dual concentric volume pot, because as it is ... what good is having two tone controls when they cannot be separate? No good to me.

Thanks again ... and back to work
Tony

 

[Artie]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

As luck would have it, you picked the one SD schematic that has a mistake in it. There should be a ground connection on the unused lug of the volume control.

Also, one of my earlier comments may have been misleading: You still will have tone interaction even with dual volumes. But there's a million guitars out there wired this way, so it may not be a big deal to you.

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

As luck would have it, you picked the one SD schematic that has a mistake in it. There should be a ground connection on the unused lug of the volume control.

Also, one of my earlier comments may have been misleading: You still will have tone interaction even with dual volumes. But there's a million guitars out there wired this way, so it may not be a big deal to you.

I discovered the mistake the hard way, and then I recalled that someone had already pointed it out here on the forum. But that's no big deal - just moving the wires around.

And as for the interaction between the tone controls - if the concentric pot (or any two volume controls for that matter) can get me anywhere near my former LP Studio, I'm a happy camper.

Thanks
Tony

 

[Tony_H]

Re: What tone pot lug do I solder the cap to? ... Not a newbie question!

And as for the interaction between the tone controls - if the concentric pot (or any two volume controls for that matter) can get me anywhere near my former LP Studio, I'm a happy camper.

Just took a look at the dual concentric pots on the Stewmac website. The two knobs are pretty tightly spaced - it'll take some practice to master it. Is that worth it ...? I'm not sure.