The Overdrive Special has a wide range of tones and can be used from clean boost to large amounts of distortion. A good initial set up would be to simply adjust the Gain controls to minimum and the output almost full

High Input jack Controls: Gain 0ne, Gain Two, Boost Output. Switches: True bypass Channel, (Gain 1-2) Boost Tone.
Standard power supply socket. Easy-fit 9 volt  (PP 3) battery compartment. Polished stainless steel housing

Channel One, will give you a clean boost.

Channel Two, with more Gain than Channel One, will result in a crunch tone.

For more distortion turn up either Gain 1 or Gain 2, but remember to turn the volume down to balance your by-pass volume.  If you wish for even more, the Boost control is there at every setting – just switch it in and adjust to the amount you want.

For more experienced guitarists, the pedal works nicely in conjunction with the guitar volume pot, so those crunch tones can be achieved by adjusting the guitar volume pot back slightly before setting up the pedal gain.

Whatever style of music you play, the Cornell-Overdrive Special has all you need for guitar lead playing.

Caution: you will need to pass a playing ability test before using the Boost Switch. A certificate will be awarded to those meeting the required standard. Operation of this switch is likely to cause war with any neighbouring public if used by any unqualified personnel.

 What Guitarist magazine says:

... the Overdrive Special has a versatility that many pedals fail to achieve while not crushing the front end of your amplifier. It's very open and cordial in its attack...