Bourns 82 Wiring

Pickups, wiring schemes, switch techniques and onboard active electronics for guitars

Bourns 82 Wiring

Postby Ansur » 28 Apr 2013, 19:00

I've got three Bourns 82 pots on the way to install in my strat.

There seems to be some confusion on how to install them, so I thought I'd just check with you guys I got the correct idea on hooking them up. I'm not an expert at all with this stuff so I might make some basic mistakes.

They'll be installed on a gold anodized pickguard, so that in itself serves as shielding and is conductive.

If I now take a typical wiring diagram, I would say these are the changes to make:
  • no extra wires between the three pots (for grounding) since that's already done through the pickguard
  • the middle tone pot needs the additional washer. that and the 3rd pot lug will serve to connect the capacitor
  • the volume pot also needs the additional washer. On that, a total of 6 wires should somehow fit:
    • the three ground wires coming from the pickup
    • a jumper from the third pot lug
    • ground to the back of the guitar
    • ground to the output jack
  • the bottom (tone) pot doesn't need the additional washer since it's already grounded through the contact with the pickguard

Does that sound about right? Anything I may have missed?



And another question while I'm at it... the schematic I referenced includes the so-called Gilmour mod in which you can activate the bridge- and neck pickup at the same time. Only, there you have to have your 5-way switch on the neck and then flick the switch to enable the bridge pickup. To have it the other way around (5-way switch on bridge, flick to activate the neck), I imagine it's sufficient to wire the bridge to the switch and then to its original location (with the neck wire going straight to its proper location)?

Also, it seems quite hard to fit these 6 ground wires all together, so if you have any suggestions on how to do that...
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Re: Bourns 82 Wiring

Postby Lucifer » 28 Apr 2013, 20:03

It's dangerous to assume that the grounding will all be through the pickguard.

What if a pot comes loose ? You lose your grounding - or at best get an intermittent crackle.

Better to put the ground wires in - or even a piece of bare tinned copper wire running across the backs of the pots and soldered to each one (put sleeves in between if you want).

The third tag from the pot is often bent back and soldered directly to the pot casing.

You'll have plenty of room then to attach the remaining ground wires.
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Re: Bourns 82 Wiring

Postby Ansur » 28 Apr 2013, 20:33

Well indeed talking about a regular pot you can indeed just solder them onto the back of the pot. Not so with this particular one. As you'll see, space is quite limited to have 6 wires connect to the washer lug.

As for the grounding - a tech once told me that if I would still attach the two wires for grounding, it would create a ground loop. Hence the idea of not including them. Isn't the chance of a pot coming loose virtually impossible what with them being physically attached to the pickguard?
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Re: Bourns 82 Wiring

Postby Lucifer » 28 Apr 2013, 22:41

Hi Ansur,

Thanks for the link showing the actual pots - now I understand why you can't solder to the back of them.

I'd still be tempted to link from one to the other for the grounding - maybe threading a piece of tinned copper wire through the appropriate tags (I forgot to look on the diagrams as to which tag was which, so this might not be possible).

A 'normal' Strat can have a ground plane (foil), AND wires to the back of its pots - creating possible ground loops - but the currents running round the circuit are so small, they don't seem to generate any hum. I would assume you are safe to run your two wires, etc, without causing hum loops.

Likelihood of a pot coming loose ? How long is a piece of string ? But pots and jacks DO come loose on guitars (I've fixed enough guitars as a tech to know this for a fact).

Good luck :thumbsup
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Re: Bourns 82 Wiring

Postby deltafred » 28 Apr 2013, 23:59

Ansur wrote:As for the grounding - a tech once told me that if I would still attach the two wires for grounding, it would create a ground loop. Hence the idea of not including them. Isn't the chance of a pot coming loose virtually impossible what with them being physically attached to the pickguard?

Sorry to disappoint you but ground loops just don't happen in guitar cavities, not enough current flowing. Power amps yes.

Sure you have a loop in your ground connection if you use the pickguard and a ground wire but it is not a ground loop it is just doubling up.

The chance of a pot coming loose is quite high, as is the jack nut.

As Lucifer points out don't rely on the scratchplate for you ground, a loose pot nut or a bit of oxidisation and you have lost your ground and it will probably hum.

The anodized finish is an insulator anyway so you have to get through that to the aluminium before you get a good connection, good quality star washers would do it but I wouldn't rely on them alone.
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Re: Bourns 82 Wiring

Postby Ansur » 29 Apr 2013, 07:43

Not disappointed, but rather glad I checked here first!
So basically, simply following the schematics should give me a good result.

As for the neck/bridge mod, is what I'm assuming correct? I know I can measure all that before actually soldering on the wires, but I'd like to be prepared as much as I can.

FYI Bourns also has a note on grounding. Nothing really new there, but as you can see on one of the pictures, it might be quite some work getting all wires to hook on that extra lug.
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Re: Bourns 82 Wiring

Postby Lucifer » 29 Apr 2013, 10:02

Hi Ansur,

The way I have achieved 'neck + bridge' on my Strat is simply to swap over the bridge and middle pickup wires at the 5-way switch.

This gives you the following: Position 5 - Neck (as before); 4 - Neck+Bridge (great); 3 - Bridge; 2 Bridge+Middle (as before); 1 - Middle

You lose the Neck+Middle combination, which many people never use, and gain the Neck+Bridge, which to me is a far more useful combination.

The modified arrangement takes a little bit of getting used to, but you can get from Neck to Bridge in just two clicks instead of four. And you have your 'top four' sounds on the top four switch positions, while the selection you'll probably use least of all (Middle pickup on its own) is way down at the bottom, out of the way.

Try it - you'll love it.
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Re: Bourns 82 Wiring

Postby Ansur » 29 Apr 2013, 10:20

That's an interesting usage of the regular 5-way switch for sure.

Though as the switch is already there I'd be left with a hole in my pickguard...
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Re: Bourns 82 Wiring

Postby Lucifer » 29 Apr 2013, 11:00

You could fill the hole with a phase switch - or a switch to change the tone cap.
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Re: Bourns 82 Wiring

Postby DrNomis » 30 Apr 2013, 12:24

Maybe even put a rotary-switch in so you can easily switch between several different tone caps...... :thumbsup
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Re: Bourns 82 Wiring

Postby Ansur » 30 Apr 2013, 18:25

Call me old-fashioned but I'm gonna stay with my original intent.

I do have a flashback signing up on the David Gilmour forum and seeing my effects collection expand rapidly. I imagine staying here will do something similar for my own modding... :)


As a side-note, I got the Bourns pots in - the wrong ones ofcourse :roll: so that'll be another week before I can hook 'em up
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