THE FRONT PANELD E I JA B C F G H KA. Input selector switches: Choose which of the three inputs to run through the Backbone. This switchalso determines what input comes out of the “SEL INPUT” XLR on the back panel.B. Left-Right Reverse: Allows you to swap left and right channels.Gains: When lit, bypasses all active electronics for the input and output gains.Polarity: Changes the absolute polarity of the signal. For more on this, see page ???C. Input Gains: 24-position, ½ dB stepped controls. From +6 to -5.5 dB.D. SUM-DIF Rotary Switch: Lets you use Inserts 2 & 3 for sum-difference (mid-side) processing. Acti-vated only when the SUM-DIF button (F in this diagram) is lit. For more info, see page ???E. Inserts 1-8: Controls which inserts are in the signal path. See page ??? for details.F. SUM-DIF Button: When lit, brings the SUM-DIF rotary switch into the circuit for processing of In-serts 2 & 3.G. Swap: Swaps the order of Inserts 4 & 5. See page ??? for info and suggestions.H. MIX-FADE Button: Brings in the MIX-FADE knob (I in this diagram)I. MIX-FADE Knob: Acts as a master fader or mixer, depending on the position of the FADER MODESWITCH (J in this diagram). For a detailed explanation, see page ???J. FADER MODE Switch: Selects the function of the MIX-FADE KNOB (I in this diagram). See page??? for more info.K. Output Gains: 24-position, ½ dB stepped controls. From +6 to -5.5 dB.