DEPENDENT
AND INDEPENDENT VOLUME CONTROLS AND YOUR GIBSON!
If you've
played Gibson style guitars such as a Les Paul, SG or 335 for any period of
time, you'll likely be familiar with how their volume controls work. Despite
having two volume controls, one for each pickup, they don't work completely
independently to one another. There is still some interaction between each
control/pickup but perhaps most notable is when in the middle position and you
roll down one volume control, it cuts the entire signal. This is because the
volume controls are dependant of one another, rather than fully independent.
They've been wired this way for decades, and whilst most players are either
simply used to it that way or actively prefer it (even making the most of it
and using the controls as a form of kill switch too for example!), there are
players that really don't like it and desire independent controls in their
guitars.
So hopefully this little article will look at why they're like this, how
you can change it if that's something you'd like to try, and what
benefits/downfalls there are to each style. Maybe it will help you decide which
is right for you and how you like to use your guitar's controls.
Traditional 'dependant' or 'coupled' Volume controls
So this is the method of wiring more than likely inside your Gibson style
guitar. As you can see from viewing the link to the diagram below, your pickup
wire is going to it's relevant volume pot's 'input' lug. With the wire going to
the pickup selector switch connecting to the pot's sweeper, or 'output' lug in
the middle.
Traditional '50s' style Les Paul wiring diagram
One benefit of this wiring style is that the somewhat 'natural' loss of treble
frequencies found when rolling down your volume pot is slightly more manageable
and useable for the player, or can certainly be improved upon by a simple
'treble bleed' mod, such as 50s style wiring, or an additional cap and resistor
combination adding between those two input and output lugs. The downside is
that when in the middle position, when you roll down one pickup's volume
control all of the way, your signal will cut out completely. Despite having the
other pickups volume control turned up. As mentioned earlier, this is the
method most players will be familiar with, even using it as an effect like a
kill switch for example. But if you've ever wondered why this method is the
'standard', and that surely having those volume controls working fully
independently would be loads better, then hopefully the below info
will help indulge that curiosity.
'Independent' or 'Decoupled' wired volume controls
So with the more traditional, commonly found dependant wired controls briefly
covered above. Let's look and how those volume controls can be wired to
function 'independently' so to speak. It's simply done by reversing the
above connections regarding the input and output of the volume pot. Your
pickup signal wire now needs to be connected to the middle, sweeper 'output'
lug of the volume pot. With the switch wire to the 'input' lug of the volume
pot instead. This style of wiring and how the controls work may suddenly become
familiar to you if you have ever played, or wired up say, a Fender Jazz bass
for example. This allows the volume controls to work somewhat independently to
each other, but it's not quite as simple as putting the cover back on and
enjoying your new decoupled controls. You've essentially changed the way the
pickups and circuit interact, which does actually affect resistance. What that
means is you will likely experience a more dramatic effect on the treble
frequencies through even minor adjustments to each volume control. So although
this still happens with dependant volume controls, it is far less drastic than
with this wiring method.
Independent 'decoupled' 50s Les Paul wiring diagram
But if it has such a negative effect on the volume pot sweep, then why is it
used in a Jazz bass etc? Fair question, for this I would recommend spending
some time playing a Jazz bass, getting a feel for it's controls and how it is
wired. I say this because it still isn't really an 'ideal' solution, especially
so because the tone pot is at the end of the circuit making for some quirks in
interaction between the volume and tone controls. 'Humps' in adjustments and
again, the loss of treble upon roll off of each volume. In a bass of course
that treble loss might not be quite as much of an issue as it would be for most
6 string guitarists for example. Again though, you could help resolve some of
this with the use of a treble bleed mod. It may require a little trial and
error to find the value of cap and resistor, and style that suits you and gets
the best from the volume pot sweep again, but it will certainly help improve
the volume controls.
In Summary
My best guess is that the manufacturers stick with dependant wiring, and have
done for decades with models like the Les Paul for example is because it simply
makes the volume controls work more effectively than when they're wired
independently, despite the signal cut off compromise. Whether it is perfect for
you one way or the other, that's for you to decide ultimately! But I hope this
little article helps you in making your decision or perhaps with some
experimentation. It's a simple mod to do if you're comfortable with a soldering
iron, so if you have a lazy Sunday spare, give it a whirl! See which method
works for you, maybe the compromises either way are outweighed by the
advantages.
As always, if you are taking on any guitar mods or wiring work, be sure to have
the correct tools and take care of yourself and your guitar.
Although these wiring diagrams are on public display here in this article, It
is important to note that the diagrams correspond to my harnesses and wiring
work I have done, and more importantly, the specific components I use within
those harness kits. So if you are wiring something up yourself, there is a
chance you're using components different to those displayed on these diagrams
so they may, or may not match up. So please double check your components,
ensure they're the same type as those displayed on my diagrams to help ensure
when you follow the diagram you wire it all up correctly. I cannot hold any
liability for issues from choosing to follow one of my wiring diagrams as these
are free to use and all risk is upon yourself.
James
Have you made good use of some of the free resources here? Wired up your guitar
or found useful info here along the way? Perhaps you might consider kindly
supporting this free resource for guitarists via 'Buy me a
coffee'! Thank you so much!
July 21, 2021 — James P Gascoigne