G
ETTING THE MOST FROM YOUR
SONOGRAPHE SA120
The Sonographe SA120 offers a remarkable degree of refinement in
music reproduction, but it cannot transform an inferior stereo system.
Only the very best loudspeaker systems will be capable of fully revealing
the capabilities of this precision instrument. On the other hand, the
SA120 is capable of revealing faults in the phono system which may not
be discernable with an amplifier of lower resolution.
Proper set-up is important in any high-fidelity system. Before installing
the SA120, be sure that your phono system has been set up carefully
according to manufacturer recommendations. Adjustment of the car-
tridge vertical tracking angle can be especially critical with modern
stylus configurations.
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 your
stereo system, these transients are created by your loudspeakers. 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 cartridge
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). If your system has an odd
number of inversions, then you must add one phase inversion. This is
conveniently done by reversing the positive and negative connections
on either your cartridge or your speakers (be sure to reverse both
channels).
Sonographe SA120 Owner’s Manual
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