Explaining a Treble Bleed Circuit: What is it? Why would you need one?
Explaining a Treble Bleed Circuit: What is it? Why would you need one?
Written by: Kenny Prochazka
Some of you may have heard the term 'treble bleed' before, but may not be sure of what it is or what it does. There are a few different takes on the idea but, at its most fundamental, a treble bleed is a tiny component that can make a big difference in your guitar tone.
Have you ever noticed that turning down your volume control seems to make your tone darker? If so, then you are the perfect candidate for a treble bleed circuit, which helps to retain your high-end (or treble) when decreasing volume by allowing some high frequencies to 'bleed' through. This can increase perceived volume, as well as do wonders for the clarity of your sound.
By attaching one end of a capacitor (we like to use a 471pF cap) to the center lug of the volume pot, and the other end to the input lug, you can effectively retain brightness at the level you prefer. However, adding only a capacitor runs the risk of the guitar's tone being overly bright, because human ears will hear it as a decrease in the lows as well. This is why our much-loved Mojotone Volume Mod also has a 220K resistor in parallel with the 471pF capacitor, to tame that brightness a bit and preserve the natural chime of your guitar.
For each instrument, each player and each setup, there may be a different preference in the values of both capacitor and resistor. In general, lower capacitor values will lead to higher frequencies 'bleeding' through, and higher values will allow lower frequencies through. In a similar fashion, lower values in the resistor will tend to brighten the tone while higher values will tend to darken it. It definitely takes some experimenting to get your perfect tone, but a 471pF capacitor in parallel with a 220K resistor is a great starting point.
There are some players who prefer the quirk of volume controlling tone, and elect not to use a treble bleed, but most of us prefer to hear all of our tone throughout the volume sweep, and a treble bleed is the most direct way to get there. Don't be afraid to experiment, and don't settle for less than what you want to hear. Go find your sound and love your tone.
Have you ever noticed that turning down your volume control seems to make your tone darker? If so, then you are the perfect candidate for a treble bleed circuit, which helps to retain your high-end (or treble) when decreasing volume by allowing some high frequencies to 'bleed' through. This can increase perceived volume, as well as do wonders for the clarity of your sound.
By attaching one end of a capacitor (we like to use a 471pF cap) to the center lug of the volume pot, and the other end to the input lug, you can effectively retain brightness at the level you prefer. However, adding only a capacitor runs the risk of the guitar's tone being overly bright, because human ears will hear it as a decrease in the lows as well. This is why our much-loved Mojotone Volume Mod also has a 220K resistor in parallel with the 471pF capacitor, to tame that brightness a bit and preserve the natural chime of your guitar.
For each instrument, each player and each setup, there may be a different preference in the values of both capacitor and resistor. In general, lower capacitor values will lead to higher frequencies 'bleeding' through, and higher values will allow lower frequencies through. In a similar fashion, lower values in the resistor will tend to brighten the tone while higher values will tend to darken it. It definitely takes some experimenting to get your perfect tone, but a 471pF capacitor in parallel with a 220K resistor is a great starting point.
There are some players who prefer the quirk of volume controlling tone, and elect not to use a treble bleed, but most of us prefer to hear all of our tone throughout the volume sweep, and a treble bleed is the most direct way to get there. Don't be afraid to experiment, and don't settle for less than what you want to hear. Go find your sound and love your tone.
6 comments
Although I know the basics it was an interesting read. Thanks.
What is always never mentioned is the value of the volume control.
I believe that the 470pf/220K values called out here are for 250K volume controls common to Fender and other types.
However, Gibson guitars and others may use 500K volume pots.
How to convert? Rule of thumb: If you double the resistance then you halve the capacitance.
In this case, for a Gibson 500K volume pot, the new values would be:
R = 220K x 2 = 440K (470K is probably close enough) and
C = 470pf / 2 = 235 pf (either 220 pf or 270 pf are standard values and probably close enough)
Responding to Gordon: Yes, there are 471 pf capacitors. The third digit is the number of zeros. 471=470, 472=4700, 473=47000 etc, all in pf.