Zapco AG Reference-series - Manual (Page 18)

17
Setting Your Gains
Proper gain setting is one of the most important factors in setting up
a stereo system. At the same time, gain setting is most often done wrong.
Turning up the gain of an amp is the very last thing you should ever do to a
system.
An amplifier is a step up transformer. Period. Any signal you put in
is boosted by a fixed factor. Music, hiss, or any other noise, it doesn’t
matter.
A large number of noise problems are simply a matter of improper
gain settings. The goal of gain setting is to achieve the maximum amount of
musical output from the amplifier while getting the least amount of hiss or
noise from the system.
Your Reference Series amplifier accepts an extremely wide range of
input levels. As little as .25 volts on the RCAs to as much as 16 volts with
SymbiLink™ balanced inputs. The basic gain setting is very simple and
requires no special tools. Whether you have a simple system with a deck
and an amp, or a system with a deck, line driver, equalizer, crossover, and
amp, the procedure is always the same.
First, hook up the system with all gain controls at minimum (turn the
gain pot fully counter-clockwise with a small screwdriver). Then turn on the
head unit and turn up the volume. If you achieve clean sound, and, more
volume than you want, you don’t need to make any adjustments. However, if
you turn up the volume and begin to hear distorted sound before it becomes
loud, you are clipping (distorting) the deck (probably a little over ¾ volume).
Turn the deck down just enough to hear clean sound again, and then move
to the next component in your system. With the deck playing at “maximum
clean volume” adjust the gain of the next component to its “maximum clean
volume”. If you adjust your gains this way, always starting at the head unit
and working down the line to the amplifier, you will get the most
performance out of your amplifier(s) with the least amount of unwanted
distortion and noise.