Understanding 100K Reverse Log Pots

Precise

Versatile

Compact

Reliable

Efficient

A potentiometer's taper describes how its resistance changes as the shaft rotates.

• Linear (B taper): Resistance changes at a constant rate. At the halfway point of rotation, the resistance is 50% of the total.

• Logarithmic (A taper): Resistance changes slowly at the beginning of the rotation and more steeply at the end. This is also called "audio taper" because it matches the human ear's non-linear perception of volume.

• Reverse Logarithmic (C taper or Anti-Log): Resistance changes steeply at the beginning of the rotation and tapers off towards the end. This is essentially a logarithmic pot wired in reverse.

A 100K reverse log pot has a total resistance of 100,000 ohms and a taper that quickly reaches most of its resistance value early in its rotation.

4 gang 100K R log potentiometer

Applications

100K reverse log pots are typically used in circuits where:

• The control needs to work "backwards" relative to a standard log pot (e.g., in left-handed guitars or specific EQ circuits).

• A "fade-in" effect or a control that acts quickly at the minimum setting is desired, such as some stompbox drive controls.

  
  

Practical Recommendations

• Choose a 4 gang potentiometer with smooth rotation for precise control

• Ensure compatibility with voltage and current requirements

• Use in applications where space-saving is critical

• Regularly clean and maintain to avoid noise and wear

Alternatives and DIY Solutions

If a specific 100K reverse log pot is difficult to source, alternative methods are often used in DIY electronics:

• Wiring a Log Pot Backwards: The most common solution is to use a standard 100K logarithmic (audio taper) pot and wire the outer lugs (1 and 3) in reverse. The pot will function with a reverse log taper, though the knob will turn in the opposite direction of a standard control.

• Modifying a Linear Pot: A linear potentiometer can be made to approximate a reverse log taper by adding a fixed resistor. A common suggestion is to use a 500K linear pot and place a 120K-127K resistor across lugs 2 and 3 to approximate a 100K reverse log taper.

• Sourcing Online: Electronic component suppliers like Blore Edwards typically stock specific reverse logarithmic pots.

Final Thoughts on Multi-Channel Control

Efficient

Compact

Reliable

The 4 gang potentiometer is a powerful tool for managing multiple electronic signals simultaneously. Its compact size and precise control make it indispensable in audio, lighting, industrial, and musical applications. For those seeking versatile and reliable control components, this device offers unmatched value.

Explore more about the 4 gang potentiometer and enhance your projects with advanced multi-channel control solutions.