The
Fender Bassman was the first amplifier to standardize the tone stack design. Dubbed the 5F6-A from the Fender model number of the amp which first used it, this tone stack offered the performer the ability to control the amplifier's low, mid, and high frequency response independently. The simplest tone stacks are derived from a
bridged T network implemented with resistors in place of inductors, creating a
notch filter. These will utilize 3 capacitors and 3 resistors in the form of potentiometers. ==References==