The sound-shaping magic of the Guitar Volume Pot and the Treble Bleed Mod
MINIMAL EFFORT - MAXIMUM EFFECT
Great guitar tone comes from many places: your fingers, your playing style, your amp, and your guitar. So it’s probably fair that we should devote an equal amount of time to each of these pillars of axe epicness. We spend most of our time on here banging on about ways to tweak your amp, so today we thought we’d share with you a lesser known guitar volume pot modification that can help take your tone from average to awesome. We’re talking, of course, about the infamous treble bleed mod…
Let’s face it: state-of-the-art guitar amps are ridiculously versatile.
They offer an abundance of tonal flavors, the sheer variety of which would have been unthinkable just a couple of years ago. Few of us have cause to spice our sonic stew with so many different seasonings; even players in versatile covers bands, who have to cover a lot ground tone-wise, can make do with a dozen sounds or so.
The sound-sculpting options these days boggle the mind, given the wide range of preamp tones that may be combined with different power amp settings.
However, this does not deter guitar amp designers from going all out in their efforts to expand the palette.
We’re spoiled for choice, and it’s easy to lose one’s way in search of the perfect sound for this or that number. It’s like the ancient knight said to Indiana Jones when he was faced with so many chalices: “Choose wisely.”
Those all-important in-between tones
But even if you’ve chosen wisely and found your Holy Grail tones, there’s still some sonic territory to be explored in the places in between.
Yep, even if you’re rocking a mega flexible rig like this one, there could still be unexplored tones out there just waiting to be discovered!
Besides, fussing with tone just as much fun as sampling your way through the menu at the legendary House Of 111 Beers pub in Munich, Germany, and not nearly as painful the morning after.
Tone starts in your guitar
The fact is that the quest for tone starts at the guitar itself, where we have a very powerful tool for tweaking sounds in one of the most organic, musically satisfying ways.
Best of all, it costs practically nothing to add this mightiest of sonic weapons to your arsenal.
Most guitars come with a tone knob, many with a pickup selector, and some with extras such as a coil tap.
But practically every guitar comes with the one thing that could, with a little mod, become the hottest iron in your sound forge.
Virtues of the volume knob
Now be honest: how often do you really use your guitar’s volume knob?
To my great astonishment, most players I’ve talked to about this only bother with the volume pot because it’s the closest thing to an on/off switch on the guitar.
Even veteran players rarely ride the volume knob, nudging it up to accent a lick here and backing it down again for a little hybrid-picked flourish there.
Most guitar players are guilty of not making the most of their volume pots. But they’re put on guitars for a reason, folks…
There are certainly a lot of sounds to be found from one and ten on that imaginary scale, but it’s equally certain that there must a good reason why all that easily accessible and musically inspiring sonic space is going unused.
Turning down volume = turning down tone?
A little hands-on exercise will explain the problem best, so plug in and dime your guitar’s volume knob. When you turn your instrument up to 10, the guitar’s signal hits your amp with the full brunt of the pickup’s output, producing that fat, satisfying tone you know and love.
Now back off the knob to the halfway mark. What happens at the 5 position? The signal is a bit softer, which is intended, but the top end vanishes, leaving you with a sound so dense that light bends around it.
Blame the pickup and potentiometer’s resistance and the guitar cord’s capacitance for muffling your signal.
There has to be another way!
The technical details are beyond the scope of this blog, but suffice it to say that this muddy, inarticulate tone is cherished by few.
Guitarists just don’t have much use for the sound of cape buffaloes mating somewhere off in the distance.
Nope, us neither. (Picture copyright Profberger at en.wikipedia, used under the Creative Commons Attribution-Share Alike 3.0 Unported license.)
Sure, your amp can reinforce the signal, but it can’t reanimate flat-lining tone.
That dull, lifeless sound emanating from the speaker cone is beyond resurrection. The sound stays lackluster until you arrive at the lowest reaches of the control range, where the top end magically reappears.
But it’s not a triumphant return because the signal is now so soft as to be unusable.
After that, it’s the end of the line. Less than zero is a concept that works with math equations, chemical bonding, and the quantified affinity for one’s ex-partner.
But, in audio terms, off is off.
There is another way: get ready to mod your axe
Do we really want to leave all that fertile sonic soil between 10% and 90% of the knob’s control range untilled?
It would be a shame to let this land lie fallow when you could harvest a bumper crop of tones.
Just one little mod is all it takes. (Note: this tweak works best with single coil pickups, as found on Strat and Tele-style axes, which one or two of you may happen to own.)
The treble bleed mod
As you probably already knew before our little demonstration, backing off the volume knob attenuates the pickups’ high-frequency output.
It cuts more treble than bass, leaving you with bland, if not barren, tone. The remedy for this particular ill is to install a capacitor.
A capacitor, yesterday. Hard to believe this little thing could make much of a difference to your guitar tone, but read on to find out how you can use it to your aural advantage.
This is called a ‘treble bleed mod’ by folks who can wield soldering irons without hemorrhaging hot solder all over the guitar, branding themselves, or torching the cat.
Get ready for way more top end
The standard practice is to dexterously pop in a 220 pF capacitor between the potentiometer’s input and output terminals; that is, solder one wire to the lug that goes to the pickup or pickup selector and the other to the lug leading to the output jack.
This little trick works like the advance-to-go card in Monopoly. It’s a shortcut for the frequencies to bypass the pot and go directly to the output.
You don’t get to collect $200, but you do get rewarded with a lot more top end.
Smoother, more organic tones
Now your knob rolls back mainly the volume of your pickup’s bass frequencies.
This brings the level down while retaining a healthy helping of treble to lend the signal more snap, clarity and pop.
Tube amps, especially, are very responsive to changing amounts of electrical energy and react organically to the upgraded pot’s action. The gain and saturation levels decrease as you roll the knob back.
The sound cleans up nicely and stays fresh rather than growing stale as it gets softer.
Of course, the recommended values for the capacitor and resistor are not carved in stone, as you can see in this video below, but they are guidelines that work well in practice and when you are approaching the subject for the first time, and give you a first impression of the sound gain.
Different ways and possible solutions to approach the issue of treble bleed – in the end it’s always the same: A capacitor and (not necessarily) a resistor between the input and output of the volume potentiometer.
You might argue that dialing back the gain or master knob on an amp achieves the same effect, but to my ears the modded pot makes for a smoother, more musical transition.
That’s what I mean by ‘organic’.
Why riding the volume knob is a skill you should master
Riding the volume knob is also a lot more convenient for those who like to build on the bedrock of plenty of power and gain for lead lines, and bring it down on the fly to conjure a less gainy but still gritty tone for rhythm work.
This also has the advantage that rhythm parts, lead lines and fills are rendered with the fundamental frequency spectrum remaining intact, so it all feels more natural, like shifting gears on a Ferrari rather than flicking a rocket-fuel injection switch on a Honda sedan to rev up and popping a drag chute to slow down.
Once you get the hang of it, this actually works so well that you may never need to do the channel-switching tap dance to go from crunch to lead to clean and back again.
It gets the job done for many musical styles, but it’s best for genres in the blues to hard rock spectrum where the guitar is the dominant instrument.
Improved musical dynamics
I’d go so far as to say that in a band context there’s really only one way to segue seamlessly between lead and rhythm tones with the intensity of the sound remaining intact, but without an appreciable dip or jump in volume: you have to saddle up and ride the guitar’s volume pot.
Here’s what our capacitor looked like when soldered to our volume pot’s input and output terminals. Full instructions on how you can do the treble bleed mod yourself are below.
When you nudge it up here and roll it back there, it feels more like a shift in energy levels than a change in volume, and that’s what makes the dynamics of it so musical.
The philosophy of tone
So is this the philosopher’s stone for guitar players?
Nope, it’s our philosopher’s tone: the volume knob is to us players what that mythical substance was to would-be sorcerers – the secret to powerful alchemy.
And that pot not only transforms one tone into another, it also makes the most of the symbiotic relationship between tube amp and electric guitar.
Again, the musical response of tube amps to changes in the guitar’s signal level and attack is what makes them so coveted. Even if you slap the front end of your amp silly with super-sized lashings of gain, you can still coax sounds out of the amp that are clean enough to pass for most musical styles simply by easing off the volume knob.
So many capacitors to try
If you drop in a capacitor only to discover the sound is too thin or tinny for your taste, then try capacitors with different ratings.
You can also add a resistor to mitigate this effect. If you care to experiment, you may wish to do so with alligator clips before firing up that soldering iron.
These are the tools you’ll need to perform the treble bleed mod successfully. Now just make sure the cat’s out of torching distance and you’re ready to go!
Know this, though: every combination of resistor and capacitor will elicit a different response, and the pickup throws another variable into the equation.
The search for the perfect setup is like the quest for the perfect tone: it’s easy to lose one’s way in the labyrinth.
If the wealth of possibilities is too rich for your blood, try this combination: C = 1 nF, R = 150 kΩ. It’s guaranteed to work well in a Strat, and you won’t end up with piercing, icepick-like top end.
One little mod, a new world of tone
If we weigh the negligible cost and effort of installing a treble bleed against the potentially prodigious payoff, a volume pot capacitor looks to be a very smart investment indeed, particularly for tube amp aficionados.
Again, this little mod works best with single coil pickups. So heads up, Strat and Tele slingers: here’s how easily this is done!
What you’ll need:
220 pF capacitor (or one 1nF capacitor & + one 150 kΩ resistor in parallel)
Phillips screwdriver (for the pickguard screws)
Tweezers (to hold the capacitor while soldering. Note: they get hot rather quickly)
Pliers (to trim excess capacitor wire)
Soldering iron
What you’ll need to do:
- Remove the pickguard or control plate (on a Tele).
- Solder the capacitor in between the pot’s input (the lug wired to the switch) and output (the lug wired to the jack).
- Put all the parts back where they were before you started.
- Power up the amp, dial in a thick, distorted tone, and roll back the guitar’s volume knob.
- Enjoy what may be world’s most seductive guitar sounds.
What mods have you performed on your guitar? We’d love to know about them, so share your experiences in our social media channels…
A nice video that demonstrates wonderfully how many ways and possibilities there are to vary the gain and sound setting of a guitar sound. The treble bleed is also impressively demonstrated at the end of the video.
