4. Special potentiometers

For special applications, for example for adjusting the balance in HiFi amplifiers or seamlessly fading from one signal to another, there are so-called dual potentiometers. They involve the inclusion of two and sometimes even more potentiometers, some with different ID resistance.

Fender's so-called TBX pot is a special case for use in sound setting. Two pots with differing ID resistance and different resistive elements. From the outside, though, there is no discernable difference to normal dual potentiometers.

If you need two pots but do not have a lot of space, you can employ double pots with concentric shafts. These are basically two pots which are independent of each other and stack-mounted. With the aid of a special two-part knob they can be controlled independently of each other.

Concentric potentiometers are often found in the sound setting equipment of active e-basses. They belong to the rarely requested special equipment and come with a price tag to prove that!

Dual pot and concentric pot with knobs

Besides the potentiometers we have already discussed there are also special construction types in which a potentiometer is combined with a switch or switches. The best-known among those are the push or pull potentiometers. They have a switch wich is depressed (push) or lifted (pull). They are available as push-push and push-pull versions, but the former are reputed to suffer more form wear and tear.

Monopolar and bipolar switches featuring the ON/ON sequence are common, so that switching is possible. In electric guitars such potentiometers are often used to split humbuckers.

Fender's so-called „S1 switch“ is a special case. It features an unusual four-phase ON/ON switch which allows for altering a stratocaster's complicated circuitry from parallel circuit to serial circuit.

Various push-pull pots

S1-Switch

The so-called No-Load-Pot“ is another special design. Also used by Fender, these pots have the clockwise lug disconnected from the resistive strip within, resulting in infinite resistance between the wiper and the other outer lug when turned fully clockwise. These are sometimes used as tone controls, to remove the load on the pickup(s) presented by the pot and the tone capacitor when turned to 10.

Potentiometers for guitar electonoics are usually only avaiable at specialised music retailers thanks to their axes, additional switches, special parts, etc. Of course you can acquire pots from many electronics webstores, but they might not meet your requirements.