Push/pull volume knobs to bypass Tone?

[sumitagarwal]

Hi folks, I've been a long-time 4-knob Les Paul guy who's recently picked up a killer Explorer that I'm loving.

I've always liked the 4-knob versatility on an LP to have independently-tweaked sounds ready at the switch. The Explorer is 3-knob (2 vol, 1 tone) and so it's slightly less versatile in that way.

To gain back some of that I'm trying to figure if I can independently disconnect each pickup from the Tone knob via push/pulls on their respective Volume knobs. I think the difficulty is that the Tone pot is after the pickup selector..
​​​

 

[marcello252]

let me understand, you want an indipendent switch to cut off the tone pot on every vol pot?

 

[sumitagarwal]

let me understand, you want an indipendent switch to cut off the tone pot on every vol pot?

Correct! My typical usage is tones at max, but sometimes I like to dial down one of the pickups so I can quickly switch from a searing tone to a mellow tone. Also on 4-knob guitars there are some interesting middle positions with tone up on one pickup but down on the other (i.e. switch in the middle with tone at max for neck pickup and at minimum for bridge pickup)

 

[freefrog]

I'd mount some concentric pot.

 

[sumitagarwal]

I'd mount some concentric pot.

Considering this, but can't find any concentric version of a traditional gold bell knob. Is there some other thing that might work? Maybe a bell knob on top of some kind of ring?

 

[sumitagarwal]

I'm sure folks would hate this idea, but what about taking old-school Gibson-style knob pointer washers, cementing tiny nuts onto them, and then putting a set screw through those nuts onto a concentric pot?

 

[freefrog]

Considering this, but can't find any concentric version of a traditional gold bell knob. Is there some other thing that might work? Maybe a bell knob on top of some kind of ring?

Yes, a concentric pot will necessarily look different... I was thinking to those used for pedals. Example:

https://www.musikding.de/Alpha-Pot-9mm-500k-lin-dual-concentric

[NOTE - There's dedicated knobs in the package of such pots. They look a bit like smaller Telecaster metal knobs.]

It should be possible to hollow out a plastic bell knob then to put it above the upper part of such a pot...

...but a bell knob and a ring under it would be difficult to set on the fly, IMHO.

Sadly, I don't have other ideas to share - except drilling a hole for a second tone pot, of course.

Hope you'll find a solution.

 

[AlexR]

If its a master tone then you cannot separate out the effect of the tone to one pickup at a time.....as in it will be on all pickups or none.

But the wiring aspect is straightforward with a push-pull, you simply take the wire that goes to the tone circuit and attach it to the centre lug of one side of the switch, with another wire going from one of the other 2 inline lugs to the tone pot.

 

[eclecticsynergy]

Actually it can can be done individually using two push-pulls.
Just disconnect the center lead from the toggle switch, then wire the switch's center lug directly to the output jack.
Run a short jumper from each volume pot's input* to one center lug of its push-pull DPDT.
Then connect the corresponding outer lug (further from the round casing) of each push-pull to the tone pot's input.
That's assuming you want the tone engaged except when the knob is pulled up.

Does not actually give you individual tone controls, of course.
But it allows you to bypass the tone control separately for each one.

* Could also tap from the center lug of a pot instead of the one where the pickup connects.
This would keep the sound a little brighter as the pickup is rolled back.

 

[GuitarDoc]

It's so much easier to use a mini switch to bypass the tone pot than a p/p pot

 

[sumitagarwal]

It's so much easier to use a mini switch to bypass the tone pot than a p/p pot

You are correct.

I am also thick-skulled in my aversion to drilling holes.

I also have 20 years of comfort using push-pulls and I know the ergonomics work just fine for me.
​

 

[GuitarDoc]

For easier and faster use you could consider a push/push pot.

I find that some push/pull pots can be a bit difficult to lift up on the fly.

 

[sumitagarwal]

For easier and faster use you could consider a push/push pot.

I find that some push/pull pots can be a bit difficult to lift up on the fly.

Always been curious about these! Especially would avoid the occasional flinging off the knob when pulling on one with a loose fit.

I always thought the Fender S-1 switch design with the push-push button inside the knob ring was really cool, and surprised it's not more common.

 

[Mincer]

Always been curious about these! Especially would avoid the occasional flinging off the knob when pulling on one with a loose fit.

I always thought the Fender S-1 switch design with the push-push button inside the knob ring was really cool, and surprised it's not more common.

I think the S-1 isn't more common because it is expensive, and uses a proprietary Strat knob- not good if you have a non-strat. I love the S-1 and use it frequently. It is the most durable and elegant (and invisible) switch for this sort of thing. Regular push pulls are terrible if you have Strat knobs (hard to grab), but I've never accidently pulled a knob off. Push-push pots aren't super common, and the few I've tried had to be replaced every few years.

 

[ehdwuld]

Ummmm no load tone pots are a thing

 

[freefrog]

eclecticsynergy : brilliant and elegant solution IMHO. Thx for sharing! I had a vague intuition it could be done. Was too buzy and tired to think about it. The pic of a light bulb came to my mind when I've read your post.

Regarding the idea evoked by ehdwuld: I've recently mounted a Fender TBX pot on an Explorer. @ 10/10, the load is of 1M. I've used the center position, theoretically "no load" as a way to promote the high mids (thx to a low value cap, 1nF in this case. Maybe I'll mount a 2,2nF or higher later). From 4,5 to 0/10, the 250k tone control is enabled and works like a normal one, with a 22nF cap. Fulfils the needs of the user, with three shades: clean n' bright full up, greasy middy but still tight @ 5/10, mellower and darker under 5.

FWIW.

 

[sumitagarwal]

Thanks for all the insight, folks!

This Explorer had a wacky setup with an EMG 81 in the bridge and an SD 59 in the neck. Worked better than you'd think! But not what I had in mind for this guitar and since I already have so many PAF-style guitars I through an EMG 60 in the neck. Since that required wiring changes anyway, I used solderless EMG stuff I had in a drawer.

But wow, between the battery, solderless connectors, and excess wire length the Explorer runs out of cavity space FAST. If I'm going to do anything fancy, whether concentric pots or push/pulls, I am very much going to need a solution to create more space first. Possibly redoing the guitar again with solder =/

 

[ehdwuld]

eclecticsynergy : brilliant and elegant solution IMHO. Thx for sharing! I had a vague intuition it could be done. Was too buzy and tired to think about it. The pic of a light bulb came to my mind when I've read your post.

Regarding the idea evoked by ehdwuld: I've recently mounted a Fender TBX pot on an Explorer. @ 10/10, the load is of 1M. I've used the center position, theoretically "no load" as a way to promote the high mids (thx to a low value cap, 1nF in this case. Maybe I'll mount a 2,2nF or higher later). From 4,5 to 0/10, the 250k tone control is enabled and works like a normal one, with a 22nF cap. Fulfils the needs of the user, with three shades: clean n' bright full up, greasy middy but still tight @ 5/10, mellower and darker under 5.

FWIW.

I dont under stand how a dual concentric pot is the equivalent of a no load pot
that sound not right

But its yours
Have fun

 

[freefrog]

I dont under stand how a dual concentric pot is the equivalent of a no load pot
that sound not right

But its yours
Have fun

My attempt to share of yesterday at night was effectively not clear at all...

Buttt... the 250k part of a stock TBX (not mounted, without components) is a no load control in center position. That's how Fender designed it.

The 1M part is half conductive, half resistive. Its resistance is of 0 Ohm from 0 to 5/10 (center position) then rises from 0 Ohm to 1M between 5.1/10 and 10/10.


This control as I've installed it in an Explorer works as following:

*From 4.5 to zero, it's a normal 250k tone control, since I've fitted the 250k part with a regular 22nF (0.022µF) tone cap.

*At 5/10, the resistive load of 250k is disabled.

*The center lugs of both controls are connected to each other and to the "hot" side of the output jack.

*On the 1M part, the right lug is connected to nothing. The left lug is connected to a 1nF cap (0.001µF) going to ground. So this part works as a 1M tone control with a low value capacitor, trimming the high range but leaving the hi-mid intact.
That's where I've not been clear at all: the control is never in no-load mode in the strict meaning of this word, since it involves a capacitive load in center position... Now, a low value cap has a paradoxical action: it shifts down the frequency of the resonant peak but makes it narrower and peakier. So the sound becomes focused in the hi-mid, more nasal (albeit still natural if the capacitor has a low value... Beyond 3.3nF it would start to sound more "artificial" / cocked wah).
Once the 250k part engaged, the related resistive load is added to the circuit and makes the resonant peak rounder. The sound is still mid-centric but mellower and will progressively get flatter then darker from 4.5/10 to 0/10 since it works like a normal tone control...

To sum it up:
Pot full up = 1M load between pickup and a 1nF cap to ground. The sound is almost as bright as with a pot in no-load mode.
Pot @5: no resistive load, low capacitive load. Mid-focused resonance, nasal tone.
Pot from 4.5 to 0/10: 250k tone control engaged (while the 1nF cap is still active). This 250k resistive load added to the capacitive load = mellower sound, going darker if the pot is lowered more than this.

I've wasted our time to explain that for one single reason: the user is happy with the result. Hence my attempt to share here (apparently bugged by our old friend covid who is again "loading" my body. "LOL").

I'll post a schematic later, with graphs showing what happens exactly.

 

[GuitarDoc]

Thanks freefrog for that explanation. I've installed several TBX controls and that is exactly what I hear. I theorized just what you have described...now I know perfectly what is actually goin on, confirming what I thought.