Yamaha MG12 Owner's Manual - Page 9

Making the Most Of Your Mixer 2. Where Your Signal Goes Once It's Inside the Box At first glance the block diagram of even a modest mixer can look like a space-station schematic. In reality, block diagrams are a great aid in understanding how the signal flows in any mixer. Here's a greatly simplified block diagram of a generic mixer to help you become familiar with the way these things work. 2-1. Greatly Simplified Mixer Block Diagram Input Channel Master Section Signals from the mixer's other input channels (if they are assigned to this master output or "bus"). 1 2 3 4 5 ■ Input Channel 1 Head Amp The very first stage in any mixer, and usually the only stage with significant "gain" or "amplification." The head amp has a "gain" control that adjusts the mixer's input sensitivity to match the level of the source. Small signals (e.g. mics) are amplified, and large signals are attenuated. 2 Equalizer Could be simple bass and treble controls or a full-blown 4-band parametric EQ. When boost is applied the EQ stage also has gain. You can actually overload the input channel by applying too much EQ boost. It's usually better to cut than boost. 3 Channel Peak LED & Fader The channel peak LED is your most valuable tool for setting the input "gain" control for optimum performance. Note that it is located after the head amp and EQ stage. ■ Master Section 4 Summing Amplifier This is where the actual "mixing" takes place. Signals from all of the mixer's input channels are "summed" (mixed) together here. 5 Master Fader & Level Meter A stereo, mono, or bus master fader and the mixer's main output level meter. There could be several master faders depending on the design of the mixer-i.e. the number of buses or outputs it provides. MG12/4FX 9