G
ETTING THE MOST FROM YOUR EVOLUTION
20
The conrad-johnson Evolution 20 offers an unparalleled level of sophis-
tication and refinement in music reproduction, but it cannot transform an
inferior stereo system. Only high quality amplifiers and loudspeaker
systems will be capable of fully revealing the capabilities of this preci-
sion instrument.
Given a system of high quality components, there remain a number of
important details which must be attended to.
ABSOLUTE PHASE
Musical notes are heard through the ear’s response to waves of alter-
nating rise and fall of air pressure. Musical transients are exclusively
positive: that is, the initial effect is a rise in pressure. The ear is capable
of distinguishing these positive transients from the musically unnatural
alternative of a negative transient (an initial fall in air pressure). In terms
of your stereo system, these transients are created by your loudspeak-
ers. If the speakers respond to musical transients by first moving out,
they are creating a rise in pressure, and the system is said to be "phase
correct". If they respond by moving in, they create a fall in pressure and
the system is said to be phase inverting. Each component in the stereo
system is either phase correct or phase inverting (including the source
and speakers-these are normally phase correct). It is of no conse-
quence if an individual component is phase inverting, as long as the
system as a whole is phase correct. This will be the case as long as the
number of phase inversions is even (or zero).
The line stage of the Evolution 20 is PHASE INVERTING. It inverts the
phase of all inputs, including phono. If your system has an odd number
of inversions, then you must add one phase inversion. This will be the
case if the Evolution 20 is the only unit in the chain that inverts phase.
THIS IS CONVENIENTLY DONE BY REVERSING THE POSITIVE
AND NEGATIVE CONNECTIONS TO YOUR SPEAKERS (be sure to
reverse both channels).
If you are not sure about the phase of every piece in your system, you
can establish correct absolute phase by careful listening. When the
EVOLUTION 20 OWNER’S MANUAL
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