A major part of Les Paul’s original vision for the solidbody electric guitar was to incorporate features crucial to studio musicians, and that dream was realised in the famed Les Paul Recording Model of the 1970's.
It has two Low Impedance humbuckers, stacked and angled. It was designed to sound best when plugged into a mixing desk at (Low Impedance setting). When used with a regular amp, you had to engage the inbuilt impedance transformer. Controls were relatively complex: Volume, Treble, Bass, “Decade,” Microphone Volume, Pickup Selector, Tone Switch and Phase Switch on its large inlay panel.
The Decade switchwas designed to “tune”/alter treble harmonics, for "biting" or "silky" highs.