Switchable Mono/Stereo Setup – Wiring Help

[alexinasuitcase]

Hey, my first post here!

So I’m wanting to modify a Squier Bronco Bass and wanted some help with working out the electronics and wiring.

I’ve not personally seen this done before, so I’m not 100% sure whether what I want to do is actually possible (so if not please let me know), and I am aware there are other ways of achieving what I’m going for, but if I can do it this way that would work best for my needs.

Essentially I want to install a second pickup on the Bronco, and have the option of either mono or stereo output but from one jack output. As far as I can tell this would be achieved by using an SPDT/on-on switch to switch the output between mono and stereo(?).

I have had a look but I can’t seem to find any wiring diagrams for this setup. I’ll be wiring this up with my dad as I don’t have much of a clue when it comes to electronics, but he doesn’t have much of a clue when it comes to guitars (great combo!) but as long as he has a diagram he’ll be able to do it no problem.

I have attached a very un-technical image of the components I’m wanting included – two pickups, individual volume controls for each, and a master tone, a 3-way toggle switch which would work in the usual way when in mono (obviously I would need to be in the middle position when in stereo), and then as I mentioned, a stereo output jack that can be switched between mono and stereo.
Whether it complicates matters or not I don’t know, but if it would make things easier to sacrifice separate volume controls for a master volume + blend pot then that would also be an option.

Like I said, I know there are other more common ways of achieving a stereo/mono setup, like having 2 seperate output jacks, one mono and one stereo (basically a Rick-o-Sound kind of thing – this would be my favoured plan B), or I think Billy Sheehan just uses two mono cables at the same time for his stereo rig. I have seen other methods too, however I would like the simplicity (externally at least) of having a single jack input, and be able to use a mono or stereo cable in there dependent on the situation I’m in.

Patiently awaiting a response to either make or destroy my dreams... TIA!

 

[Reedt2000]

This should be doable. Get a stereo jack first. You want to shunt the ring lead (hot from one of your pickups) to tip of the jack for mono operation. I'd use a push/pull pot to do the switching, it should look cleaner.

Pretty sure your dpdt will be wired like this:

But I'm gonna page @AudioTaper and @Jon Clegg to check my work

 

[Jon Clegg]

Yep, that will do it. If using a push-pull, verify the sense of the switch (what's connected to what when pulled) with a meter before connecting the pickups, etc.

 

[Jon Clegg]

Yep, that will do it. If using a push-pull, verify the sense of the switch (what's connected to what when pulled) with a meter before connecting the pickups, etc.

I'll add that using a switch is far less frustrating than the dual jack option; I'm always plugging into the wrong jack.

 

[Reedt2000]

Yep, that will do it. If using a push-pull, verify the sense of the switch (what's connected to what when pulled) with a meter before connecting the pickups, etc.

Thank you

And yes, you'll need to know what position connects which pins. The positions on the switch do the following:

You'll want the down position to be whichever configuration (mono or stereo) you'll use most.

 

[alexinasuitcase]

Thanks guys – this is super helpful, and also good to know it’s possible!

In terms of the rest of the wiring, are there any existing diagrams I could use as a basis for this?

The separate volumes master tone is basically a JB setup, but I’m not sure how I’d then go about incorporating the toggle switch and accounting for the stereo setup.

I found the digram attached for 2 pickups, 2 volumes, 1 tone and a 3-way switch but as I say I’m not sure how I add in the stereo element to this. Can you guys help with this?

 

[Reedt2000]

With two volumes you wouldn't need the 3 way switch. Because of the stereo output, I think you'll need 2 tones as well. When you split to stereo that will give volume and tone control for each pickup. A stacked tone pot is the easiest way to fit it all, then each lead will go to your dpdt switch for the mono/stereo selection.

If I were doing this I'd remove the jack from the pickguard to free up the hole and install a barrel jack on the side. Then run volume push/pull for one pickup volume and mono/stereo selection, another plain volume for pickup 2, and stacked tone controls.

My other more electronically savvy friends can weigh in on what they think ideal configuration would be

 

[Reedt2000]

I think this is a workable diagram though I don't think you'll need the resistors.

Instead of the red and blue going straight to the jack, they'd go to the dpdt switch wired like the drawing above. Again, more experienced TBers can weigh in on if I'm right.

 

[alexinasuitcase]

Yeah my plan was to add in another control knob where the jack input was and then have a side-mounted jack, and the DPDT switch next to the jack.

Ideally I would like a maximum of 3 control knobs though as I don't require separate tones for each of the pickups, one master tone works fine for me.

The 3-way switch was for use when in mono (which will be how I use the bass most of time) so I can switch between the pickups easily rather than having to turn volumes down to isolate one pickup.

Is it possible to have the mono/stereo system which includes the 3-way and only a master tone, or is that not going to work? That's basically what I'm trying to achieve.

 

[Isaac_James]

You'll want the down position to be whichever configuration (mono or stereo) you'll use most.

This is only applicable in the case of a push/pull pot, correct?

 

[KidAmnesia]

Yeah my plan was to add in another control knob where the jack input was and then have a side-mounted jack, and the DPDT switch next to the jack.

Ideally I would like a maximum of 3 control knobs though as I don't require separate tones for each of the pickups, one master tone works fine for me.

The 3-way switch was for use when in mono (which will be how I use the bass most of time) so I can switch between the pickups easily rather than having to turn volumes down to isolate one pickup.

Is it possible to have the mono/stereo system which includes the 3-way and only a master tone, or is that not going to work? That's basically what I'm trying to achieve.

If you have both pickups conected to the same tone pot, it will blend both signals and make it imposoble to split them for stereo.
What you could use instead of two tone pots is a stacked pot where both pots are controlled by the same shaft (IIRC they are called dual gang pots) or a tone switch, a dpdt or 3pdt with one or two preset tone cuts for each pickup.

 

[Reedt2000]

This is only applicable in the case of a push/pull pot, correct?

Yup, with a switch it won't really matter, you'll just need to know which position is which.

 

[Reedt2000]

Yeah my plan was to add in another control knob where the jack input was and then have a side-mounted jack, and the DPDT switch next to the jack.

Ideally I would like a maximum of 3 control knobs though as I don't require separate tones for each of the pickups, one master tone works fine for me.

The 3-way switch was for use when in mono (which will be how I use the bass most of time) so I can switch between the pickups easily rather than having to turn volumes down to isolate one pickup.

Is it possible to have the mono/stereo system which includes the 3-way and only a master tone, or is that not going to work? That's basically what I'm trying to achieve.

I don't believe a master tone control is possible with the stereo mode, but I'm by no means an authority on the subject.

 

[bassbrad]

The 80's era Carvin guitars and basses had a mono/stereo option depending on which jacks are used. They have a 3 way switch, vol and tone for each pickup as well as coil taps and a then popular phase switch. The mono jack combined both pickups, using both jacks gave you stereo.

https://www.talkbass.com/attachments/carvin-lb50-wiring-jpg.3545142/

 

[Will_White]

I don't believe a master tone control is possible with the stereo mode, but I'm by no means an authority on the subject.

It would require a dual gang pot. Essentially acting as two tone pots tied together.

 

[Reedt2000]

It would require a dual gang pot. Essentially acting as two tone pots tied together.

Ah, I see. So essentially 2 pots operated simultaneously by the same shaft. Does such a thing exist? It would allow what the OP wants to do.

 

[Jon Clegg]

Yep
uxcell WH148 500K Ohm Variable Resistors Dual Rotary Carbon Film Taper Potentiometer 5pcs https://a.co/d/509ATkq

 

[Will_White]

Ah, I see. So essentially 2 pots operated simultaneously by the same shaft. Does such a thing exist? It would allow what the OP wants to do.

Yep, this one will do it all if OP has the cavity depth.
Link Removed

Or this one if OP wants to use a separate switch.

Link Removed

 

[Reedt2000]

So, stacked volume for the 2 pickups, 3 way selector, 2-gang tone pot, 2 position dpdt for mono/stereo, and stereo barrel jack squeezes everything the op wants in.

Now the elephant in the room, what 2nd pickup? MM between the bridge and pickguard? Mud bucker at the neck?

 

[DonaldR]

I don't think you need a switch for mono/stereo using a TRS tip shunt jack. You use a TS cable for mono and a TRS cable for stereo. Post your request in Seymour Duncan forum, they are dealing with wiring on regular basis: [Invalid or Expired Link Removed]