Yamaha 6FX Owner's Manual - Page 11

Making the Most Of Your Mixer 3 The First Steps in Achieving Great Sound Before you even consider EQ and effects, or even the overall mix, it is important to make sure that levels are properly set for each individual source. This can't be stressed enough-initial level setup is vitally important for achieving optimum performance from your mixer! Here's why ... and how. 3-1. The Head Amplifier "Gain" Control Is the Key! Let's review our simplified mixer block diagram: Each and every "stage" in the mixer's signal path will add a certain amount of noise to the signal: the head amp, the EQ stage, the summing amplifier, and the other buffer and gain stages that exist in the actual mixer circuit (this applies to analog mixers in particular). The thing to keep in mind is that the amount of noise added by each stage is usually not dependent to any significant degree on the level of the audio signal passing through the circuit. This means that the bigger the desired signal, the smaller the added noise will be in relation to it. In tech-speak this gives us a better "signal-to-noise ratio"-often abbreviated as "S/N ratio." All of this leads to the following basic rule: To achieve the best overall system S/N ratio, amplify the input to the desired average level as early as possible in the signal path. In our mixer, that means the head amplifier. If you don't get the signal up to the desired level at the head amplifier stage, you will need to apply more gain at later stages, which will only amplify the noise contributed by the preceding stages. Just remember that too much initial gain is bad too, because it will overload our channel circuitry and cause clipping. MG16/6FX 11