The ST‑SH2 is used in applications requiring headphones of any impedance to be driven from consumer or professional audio sources. For fixed level installations not requiring user volume control, the ST‑SH2 is wired to the audio source and to a headphone jack. Frequently, it is desirable to mount a volume knob by the headphone jack. The LEVEL ADJUST terminals (L) and (R) may be wired to the respective wipers of a stereo 10 kΩ potentiometer to provide volume adjustment. It is recommended that the ST‑SH2 be located less than 39 in. (1 m) from the jack and volume control.