We often get calls from people asking what value of potentiometer that they should be using for the volume controls on their guitars. As a general rule of thumb, for single coil pickups we recommend 250k audio taper pots, and for humbuckers we generally recommend 500k audio taper pots. The most basic reason for these recommendations is that it allows a smooth swell in volume from zero to full out. The purpose of this article is to show you what effect changing the value of the pot can have on your pickup's tone. Let's start with the pickup itself: a single coil pickup like our SSL-1 Vintage for Stratocaster. The SSL-1 has a DC Resistance of approximately 6.5k and a resonant peak (the pickup's voice, or sweet spot) of about 10kHz. The characteristic of an SSL-1 (and other single coil pickups) is such that when a note is plucked, the tendency is for the tonal spectrum to leap towards the peak frequency, giving that characteristic "sparkle" in the attack. The amount of "sparkle" can range from minor to overkill depending on what value of potentiometer you use to "load" the pickup's circuit with. In figure 1 you can see the peak characteristics of an SSL-1 with different values of volume pots attached to it. The top curve indicates virtually no load, the second curve down indicates a 1meg pot, the third down is a 500k pot, the fourth is a 250k pot and the bottom curve represents a 100k pot. As you can see, the peak doesn't shift in frequency, but it does shift in amplitude. The difference between a no load state and the load induced by a 100k pot is 19dB (a significant difference)! In figure 2, we show the same settings as they relate to one of our SH-8b Invader™ pickups. You'll notice that in a high output pickup, the difference is not as great. As you reduce the amplitude of a pickup's peak frequency, the surrounding frequencies come into play more and more. This can give a more pleasing balance of frequencies, and is part of the reason for the guitar manufacturer's selection of the volume control's value. What does this mean to you? It means that if you like a pickup's basic character (its peak), you can further shape the tone by increasing or decreasing value of the pot in your guitar. Have fun in your tonal quests!