API 5500 - Rear Panel Connections; Balanced Input and Output Connections; AC Power, Voltage, and Grounding

5500 Dual Equalizer API
10
True to the design of the 550, the Q is reduced in an equivalent fashion, meaning that if
6dB of boost is selected in the x1 RANGE, you will get the same amount of boost and an
identical shape of the EQ curve by selecting 12dB in the .5 RANGE. The classic subtlety
of the 550 when used at low amplitude settings is enhanced by the ability to perform
micro-adjustments of tonal color.
Mastering engineers also prefer an equalizer that has exactly repeatable switch settings
and the capability of truly reciprocal operation, features that are common to all API
equalizers.