The symetrix model 201 eq/preamp provides studio quality equalization and notch filtering for line level balanced or unbalanced signals, as well as for low level unbalanced signals. three fully parametric bands of equalization are provided, with +15db boost and -30db cut capability, allowing the sx201 to be used for both creative and corrective equalization. overlapping frequency controls cover the audio range, from 16hz to 20khz. bandwidth is continuously variable from .05 octaves (for deep notch filtering), to 3.3 octaves (for smooth tone shaping). with its separate line and preamp inputs, the sx201 will handle nearly any signal level. the line level input provides both balanced or unbalanced terminations, while the preamp input is unbalanced. the line level input is intended for use with signals that have already passed through a preamplifier. the preamp input provides 30db gain, and is intended for use with low level signals such as those from synthesizers, guitars, bass guitars, or electronic drums. the overall input level control allows the operator to set internal signal levels to match boost/cut conditions. parametric equalizers are so named because their operating parameters (characteristics) are variable. the sx201 is described as fully parametric because the center frequency, the bandwidth, and the amount of boost or cut, are all user adjustable.