Gain Staging: Difference between revisions

The accepted rule is to set your gain as HIGH as possible, as EARLY in the signal chain as possible - and adjust each consecutive gain stage until you reach the last component. This will give you maximum headroom and the best signal-to-noise ratio. Every signal carries some noise with it, and if you set your gains too low at the front (preamp/mixer/processor), and then try to compensate for it at the end (PAS), you will be magnifying the "noise" as well as the signal. The "cheaper" the equipment is that you're using in front, the more obvious this will be.

The easiest way to do this is to just VISUALIZE how your signal runs. Whatever your signal from the guitar or mic hits first - be it internal or external preamp, processor, mixer, whatever - maximize THAT trim control first. Having LED's to visually see the clipping makes this job much easier - just sing or play as loud as you plan to (turn the master down - you don't need to actually make noise to set your trims if you have LED's) and crank the trim/gain until it flashes red into clipping - then back it off a bit to give yourself some room. Then continue down the path of the signal chain - this includes any "inserts" into the chain - adjusting each component until you finally hit the PAS, which is the end of your chain.

Every piece of equipment that I've used in my PAS has benefited from this rule. I've had some pieces that had intolerable amounts of noise (the Digitech Vocal 300 comes to mind) when the gain at the Digitech was set low, and the PAS set high. When I reversed them back to the "rule" - set the Digitech gain as high as possible, and just adjust the trim at the PAS only as needed, it became a usable piece of equipment.