Empress Effects Tape Delay - Manual (Page 11)

Adjusting the Headroom
The Empress Tape Delay has an internal switch which allows for the
adjustment of the input headroom. This switch is accessed by
removing the back plate. The pedal ships with the switch in the -6dB
position, which allows for an input level of +5.1dBu. If the input to
the Tape Delay is especially loud, and you are noticing distortion
under normal conditions, you can increase the headroom by moving
the switch to the -12dB position. If the input is low, and you'd like to
increase the signal-to-noise ratio, you can move the switch to the
center position.