Does your guitar knob perform as well as you’d like?

The importance of guitar control knobs.

(Warning : This is a multi-layered article which may serve as a basis for selecting your controls on your guitar on one level, and on another level, the way you conduct your life and your psychological state of being. Use it wisely!)

How many people would be happy playing an electric guitar or bass over which they had no control of sound level or tone colour? Very few I think.

Almost all electrical systems and machinery, have some functions which can be varied by moving a control. From aeroplanes to amplifiers, medical equipment to submarines, games to guitars – they all have some little knobs that when twiddled, cause a change in direction, power, size, quantity, speed, duration, etc etc. Some are vital, others you could live without.

The knob itself, is the interface between the machine and the operator/user/player, who usually moves it with his hand or fingers. Although the knob is independent of the function, the comfort and ease of using it can affect the change it produces. To this end its shape, size and feel are relevant. On electric guitars, the usual controls are volume, tone and selector (for different pickups or sounds). Traditionally they are round, between 1/4 inch and 2 inches wide, and up to an inch high.

Does your guitar knob perform as well as you’ld like?

Components like potentiometers and switches have small metal shafts that need to be turned or moved. They can be manipulated directly, but a suitable knob enhances their accuracy and comfort. So what is a good knob? – essentially one you can get a good grip on and see easily!
First let’s look at the options.

Knobs vary in fit, size, shape, material, colour, markings and cost. For the guitarist the fit is often the most important thing. If the knob won’t stay on, or won’t even go on, it is useless! Does your guitar knob perform as well as you’ld like?

There are two basic fits for rotary knobs – push-on and screw-on. Push-on are designed to be held in place by the tightness of the splined shaft squeezed into the knob’s matching hole. Screw-on have a small grub screw on the side that locks against the pot shaft. These are easier to fit and more secure. The push-on variety can be difficult to fit, especially when the pot shaft is too wide. Don’t be tempted to force your vintage Gibson or Strat knob onto a new pot – they’re likely to crack or snap – expensive mistake! The centre hole in the knobs that have screw fit is either 6mm or quarter inch, again a problem if not matched to the shaft. Next parameter is the size. This should be sufficient to get the necessary grip. but not interfere with other close-by components.
Associated with the size is the shape. If the pot is stiff, or a push/pull type, a slippery knob may hinder operation. Knurled or rubber banded knobs (often called ‘speed knobs’), work best with these types. When it is important to know at what level the control is set, markings on the knob are essential. Usually these are numbers 1 to 10 around the rim, or a dot or line on the top or side of the knob. Perhaps someone should invent a high visibility or illuminated knob.
Metal knobs last very well but may sometimes produce electrical noise when touched (there’s always a downside!). Plastic and wood are the other commonly used materials for guitar knobs. In fact plastic is probably the most widely used material for knobs in all applications, since it can be cheaply and easily produced in a multitude of colours, shapes sizes and finishes – enough to satisfy most guitarists.
The variety of colours, shapes and designs of knobs is huge nowadays. Some are even custom matched to a particular guitar! From skulls to squares, you’re bound to find something you like.
One last word of caution. Removing tight knobs can be very difficult – hazardous to the guitar, the control, or the knob itself. Before taking the risk, consider investing in a custom designed tool for the job – a Knob Puller!