The middle control will increase the middle response as you turn it up, so the more middle the fatter or thicker the sound.
The treble controls the high frequency response, but when you increase the treble control the sound also gets fatter or thicker.
The Gain control sets the volume of the Middle and Treble, but you will get a crunch-type distortion with the gain full up. This will vary depending on the output from the pickups of your guitar.
Back view showing the internal components and the easy-fit battery compartment, the battery can be changed using your thumb nail or plectrum.
Caution: For safety reasons remember the Treble response is at its highest when the control is down. Should you increase the Gain with the Treble in this position there is a danger of cutting the heads off your audience.
The Cornell-TM Boost will get the best out of your amp without adjusting the controls for each song, just use the Cornell-TM Boost, set the tone and then simply switch it on. Remember that with the True Bypass there are 3 completely different tone responses.
This is more than just another pedal - it's a tool that you'll discover is irreplaceable.