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3 Simple Steps to Choosing Treble Bleed Values

Picking the values for a simple parallel treble bleed may seem like a headache, so lets keep this to a simple 3 steps!

Step 1 – Pick Your Cable

Our cable, both the length and material, is the main factor on the value of the capacitor we choose for the treble bleed. What difference will these make?

The capacitor we choose is basically there to offset the the capacitance of the cable! The longer the cable, the greater the capacitance. Along with this there are a variety of cable materials, and manufacturing methods, each with a capacitance difference. The higher the capacitance, the darker the tone and greater the treble loss as the volume is decreased. So pick a cable length, manufacturer and then stick with it. If you use a 10ft cable for home practice, it’s going to sound different to a 30ft cable used on stage.

Cable could be something you may not have paid much attention to before. If you’re someone who likes good quality cable then I cannot recommend enough going to a smaller custom cable maker like Chris at Practical Patch. You’d be surprised how inexpensive it is to have expert knowledge on tap to help you pick a good cable material, connector type, as well as get the stand-out style you’d really like to have on stage!

The main message here that a consistent treble bleed sound needs a consistent choice in cable.

Step 2 – Identify your Volume Pot

The reason we have a resistor in parallel with the capacitor is to stop us having too much of a brash sound from the treble bleed as we lower the volume. But this can be taken too far, and we could end up a muddy sound. The value of our guitar volume pot affects the choice we make.

The most common values of Pot used most guitars are 250kohm and 500kohm. Both of these have a different sound, with the 500k sounding brighter, hence being commonly used in Humbucker equipped guitars. Although not very common some guitars use values as big as 1Mohm!

So with this information let’s go onto step 3 and choose our components.

Step 3 – Choose Components

So armed with the information from the previous steps we now need to apply them to some rules of thumb. Kevin Kretch of drkevguitar.com kindly gave me the simple rules that he follows below. These are a great starting point for picking a capacitor and resistance value for use with the Treblemaker that can then be tweaked to your own preference.

  1. The capacitor should match the cable capacitance or maybe 100pF higher to make sure that the resonant peak stays about the same in the lower half of the volume knob sweep. So for a 10ft cable this would most likely be a 470pF, 560pF or 680pF capacitor. A 30ft cable capacitor choice would be 1nF, 1.2nF or 1.5nF
  2. The resistance would be 50% to 70% of the nominal pot value. So for 250k, between 120k and 160k. For 500k it would be between 250k and 330k. Any more than this and as we get to the lower end of the volume sweep we could lose some of the bass.

So how about adding in a series resistor? I see this as being a way to dial up or down the amount of treble bled into the signal, after you’ve gotten as close as you can with the parallel resistor. Just my personal preference. After experimenting yourself, you’ll come up with your own preference.

I would highly recommend having a look at this excellent article on DrKevGuitar.com. It has a great round up of the common values used by a lot of guitar manufacturers, some of which use a series resistor, like the Fender Tone saver. But ultimately you need to experiment yourself! It’s your own ear that needs to be happy with the final result. So grab your Treblemaker and get tweaking!

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Does capacitor material affect tone?

Capacitor choice is a hot topic in the guitar world. Debates rage between both camps as to which capacitor material has the best tone, or even if the material has any affect on tone at all.

Cropped picture of the contents of the Treblemaker kit. Focus is on the capacitors spilling out of the bag

How does capacitor material affect the capacitor?

Why are there different materials for making capacitors? Whether that be, ceramic, mylar polyester, paper in oil or the many others, the reasons for each material to be chosen are the specific electronic and environmental conditions the capacitor will be subjected to.

When a circuit is designed, we want to pick a capacitor that will give us the same characteristics and capacitance under the stressors of the application. So for instance, we would pick a different capacitor for high temperature environment, such as furnaces, than we would for a cold arctic environment. What is important is that the capacitor gives the required capacitance we need over the full range of conditions the circuit will be in.

Other factors that affect the material we choose are the the voltage and frequency requirements.

So really the material that is used doesn’t affect the capacitance per say. Actually we could say it preserves it, under harsh conditions. The harsher the conditions, the more specialised the materials have to become, and the more expensive the capacitor will be.

Here is an excellent webpage explaining the differences in behaviour between capacitor materials.

Why does this matter for guitar tone?

In general we can say that it shouldn’t. Unless you intend on gigging in an active volcano or on a glass furnace, a cheap ceramic capacitor will do the job. As guitarists we aren’t going to get any capacitor to a point it starts to fail!

More important I would say is the tolerance of the component. If I were to produce 100 wiring looms and wanted them to sound the same, then a higher priced capacitor with a 2% tolerance is going to give me more consistency than a 10% tolerance.

Another factor I haven’t mentioned is how older components, like vintage paper in oil capacitors, behave. They will give you a different tone because over time they break down and don’t operate as they should. This “vintage” tone is something a lot of players want.

I also believe I something you could call a “gear feel factor”. When you feel good about the components you’ve used, whether it’s because they’re higher quality, or replicate a certain time in guitar history, then you will feel good about your instrument, and about your tone. That will translate to how you play and how you sound! No question.

So why did I choose to supply Mylar Polyester capacitors with the Treblemaker?

There are a few reasons.

1) The capacitors have a good tolerance of 5%.

2) They’re a similar material and makeup to Orange drop capacitors. So for people who believe these capacitors give a better tone, these will be closer for them to experiment.

3) They’re physically large enough that the capacitance values are easy enough to read, I think.

4) They can operate in harsher conditions than a lot of ceramic capacitors. Right or wrong that makes me feel I’m giving that bit extra to you.

5) They look good and are only slightly more expensive than ceramic caps. I don’t underestimate the “gear feel factor” on how you feel about my products and how they’ll feel in your guitar!

So are there any capacitors you really like to use? Are there any you’d like to see as an option with the Treblemaker? Leave a comment.