Potentiometer tapers explained
22nd March 2022
What are pot tapers?
Potentiometers come in all shapes and sizes, with a few spec combinations suiting guitar use particularly well. Most players are familiar with using pots of around 250k (ohms) for single coils and around 500k for humbuckers, but, even within those widely accepted specifications, there are quite a few variations which make a big difference to how the pots respond with your rig.
Pot taper refers to the rate at which the resistance increases as you turn your pot up from zero to maximum (in the context of the pot being connected as a volume pot, this refers to the resistance between the middle (output) lug and ground).
A "Linear" pot has a completely constant increase of resistance, so, if you turn the pot 1/2 turn, you get 1/2 of the resistance and so on. This will sometimes be referred to as a "50%" pot, meaning that at the midpoint of the travel of the knob, you get 50% of the resistance. These pots are used in guitar circuits pretty commonly; more often as the tone pot, but some players also enjoy the feel of them as a volume pot too.
However, some pots do not follow this straight line of resistance increase, but, instead, follow a curve. Usually, this means a slower rise in the first part of the knob rotation, which gradually increases in rate as you get closer to full resistance. These are known as audio taper, or logarithmic pots. These pots will also be categorised with a midpoint percentage, but with the figure being less than 50%. Tapers closer to 50% will have a more subtle curve and those with lower percentages are more abrupt, with most of the rise happening in the last part of the rotation.
We now offer our custom spec CTS 280k and 550k pots in 3 taper options: Fast 10%, Medium 20% and Slow 30%. The speed of the pot refers to how responsive the pot feels at the top end of its rotation and, as we have covered, the midpoint percentage lets you know how much of the resistance is in the circuit at the midpoint of the pot's rotation.
10% gives the snappiest feel, allowing quick volume changes with a small flick of the volume knob and allows full volume swells to be effected with just around a 1/4 turn of the pot.
20% gives a great balance between a fast response and a good level of fine control.
30% gives the most gradual and predictable adjustment; great for carefully dialling in the sweet spot.
Each type doesn't give you a different tone, as they all offer the exact same range of resistance settings, they simply feel a little different in use, with some having a more sensitive response at the higher settings. It's really down to your own tastes and preferences as to which will suit you best.
Why have curved tapers at all?
The human auditory system really doesn't work in straight lines, so, the even, gradual increase of a linear pot actually doesn't sound linear to us at all; it sounds like a faster rise at the lower end, which gradually slows as it nears the top. For many years, HiFi manufacturers have known that introducing a curve to the taper of a volume control actually results in us hearing a more linear change in perceived volume. This is definitely a part of the appeal of audio taper pots, but we also have to consider the circuit that they are built into and the kind of sounds that you are working with.
When you play electric guitar, it isn't simply your guitar which is in the circuit, it's your amp and all of your pedals etc, many of which will be introducing compression and distortion into your sound to some degree unless you are always playing with a gin-clear clean tone. Because of this, a subtle reduction as you roll back from max volume may just be absorbed by the compression of your overdriven tone and you actually need a more rapid change to affect any meaningful drop in volume. Due to this, high gain players will often prefer faster pots, with more vintage orientated players enjoying the smoother response of something like our 30% option.
As with many of these guitar tweaks, there is no hard and fast rule to say which will suit you best, so, by all means, do some experimenting!