An apparatus for optically shifting the frequency of an input signal beam includes a first Raman medium that receives an input signal beam, a first pump beam, and a first reference beam to responsively generate an intermediate signal beam comprising a Raman sideband of the first Raman medium. Resistors are connected in series between the feedback node and the reference supply voltage. The transistor is connected to the LEDs in series. The insole comprises a deformable structure in its forepart. Subsequently, an audio processor key shifts a playback audio pitch associated with the audio samples to compensate for the higher pitched audio associated with the fast forward video playback mode.