Tech

Here’s how: Better sound for the Gibson Les Paul with three pickups




There is more on the subject in issue 5/21 of Make.

The guitar maker Gibson has set many standards, but not only convincing ones. For a long time they were fixated on guitars with two pickups (pickups or PU for short), such as the The Paul or the more modern one SG. All replicas follow the Gibson specifications slavishly, be it their own daughter Epiphone or copyists from China like the company Vintage.

The circuit diagram is extremely simple. With a three-position switch are in position Rhythm the neck pickup, in position Treble the bridge pickup and both switched on in the middle position. In the following I use the notation as a short form for the switch positions and the pickups that are switched on:

Neck – Neck & Bridge – Bridge



The three switch positions on the The Paul with two pickups, each of which is active, outlined in green, from left to right: Rhythm – middle position – Treble. The switch can be seen in the top left of the picture.

There is a separate one for each PU Volume– and ToneAdjuster. All four work in the middle position.

Then, however, Gibson created the Les Paul named Black Beauty with three pickups, but stayed with the three-way switch. Fender has it with the 3-way and later 5-way switch Stratocaster Made smarter (also with three pickups), but used a slot in the pickguard. This is a no-go at Gibson.

With the three possible switch positions, Gibson decided on:

Neck – middle & bridge – bridge



The three switch positions on the The Paul with three pickups, again from left to right: Rhythm – middle position – Treble. There is still room for improvement.

These three positions can all be used, but two important, tonally relevant variants are omitted. On the one hand Neck & Bridgeas usual from a guitar with two pickups. But you don’t get to hear the middle PU alone either. On the station wagon customary at Fenders Stratocaster Neck & middle you can do without it, because it sounds very uncomfortable with Gibson’s humbucker pickups. A variant that activates all three pickups at the same time sounds even less pleasant, which Fender does without.


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The problem with too many interconnected (parallel) pickups is that they dampen the resonant circuit that a pickup forms (R + L + C) too much and at the same time lower the resonance frequency. This results in an uncomfortably dull and limp sound.

Many guitarists are annoyed by Gibson’s spartan circuit diagram. The common and apparently simple remedies do not lead to optimal results. In order to accommodate an additional switch on the guitar without visually changing the instrument, a potentiometer is often used, the axis of which is pulled or pressed to switch. In the simplest case, the central pick-up is connected to the specified switch positions. You then get the following:



The potentiometer switch pressed (position 0)

Pot switch position 0:
Neck – middle & bridge – bridge

This corresponds to the Gibson standard just described for three PUs.

Pot switch position 1:
Neck & middle (new, but dispensable) – middle & bridge (like 3-PU original) – middle & bridge (a second time)



Poti switch raised (position 1)

Obviously, this is not a big hit: Just a new sound that doesn’t add much to it.

You get a little further if you first switch to the classic 2-pickup variant, i.e. first remove the middle pickup from the circuit and then switch it on using the potentiometer. That leads to:



Brand new switch potentiometer before installation

Pot switch position 0:
Neck – Neck & Bridge (new and desired) – Bridge

Pot switch position 1:
Neck & middle (new, but dispensable) – Neck & middle & bridge (new and very dispensable) – Middle & bridge (like 3-PU original, desired)

After all, you get a new sound here, which is also wanted (in addition to two more new ones that you don’t need). But here, too, there is no single access to the central PU. Another disadvantage of both solutions: the middle pickup is not assigned to any of the potentiometers, i.e. its volume or sound cannot be adjusted separately.

The switch on the potentiometers designed for guitars is usually a double switch. If you only use one of these switches, you get the following solution, which offers several advantages: You don’t just switch on the middle pickup, but switch between the neck and middle pickup.

This creates the following circuit diagram:

Pot switch position 0:
Neck – Neck & Bridge – Bridge

This is the classic circuit of a Gibson with two pickups, you want all three positions.

Pot switch position 1:
Middle (single! Finally!) – middle & bridge (like 3-PU original, desired) – bridge

This means that every pickup has one in every variant Volume– and Tone-Poti assigned.



The new circuit makes in Pot switch position 0 from the 3-PUThe Paul in principle a classic one The Paul with two pickups, as if the middle one didn’t even exist …



… in Poti switch position 1 on the other hand, you can also enjoy the middle pickup, either individually or together with the bridge PU, as with the original 3-PU circuit from Gibson.



You only have to unclip a cable on the three-way switch, so you can save yourself the need to remove it.

The conversion itself is simple: You replace one of the 500k potentiometers (typically one of the tone potentiometers) with a 500k potentiometer with a switch and reconnect it just like the original. Then you disconnect the supply lines of both the neck PU (blue in the graphic) and the middle pickup (red) where they are soldered on in the original state – with the neck PU this is one volume potentiometer, with the middle PU the 3-way switch.



Simplified wiring diagram of the original Gibson circuit for the The Paul with three pickups. It differs from the version with two pickups only in the three-way switch to which the middle pickup is directly connected. (Ground lines and capacitors on the tone controls are missing for the sake of clarity)

These two loose ends are then connected to one of the switching contacts of the switching potentiometer and its center pin is connected to the connection on the volume potentiometer to which the neck PU was originally connected (orange in the graphic). In the idle state 0 of the potentiometer switch, the neck PU is then active, in state 1 the middle pickup is instead.



Modified wiring scheme: the potentiometer selects between bridge and middle PU; otherwise the interconnection corresponds in principle to The Paul-Version with two pickups.

    • In the new Make issue 5/21 we show you how to build your own booster, a preamplifier that can not only make the actual amplifier steam, but also compensate for different guitar or effects device levels and use a single potentiometer as a control element for the Reinforce as weaken does.


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