OVATION PH 8.3
15
B asic operat ion
ℹ
NOTE
If the gain is too high, the input may be overloaded and dis
-
torted. In this case reduce the gain of the PH 8.3 by one or
two steps.
2.5 Selection of an equalization curve
There are two basic problems in the production of records
(also called "pressing"): Since most of the energy is available
in the bass range of the music signal, very large deflections
would have to be cut into the vinyl. However, the large groove
spacing required for this would reduce the playing time of the
record to only a few minutes. Conversely, the signals in the
high frequency range are very weak and would be lost in
groove noise with "linear" cutting. Therefore, the music signal
is pre-equalized during the production process: In the bass
range the level is lowered, in the high frequency range the
level is raised. Since this is a linear distor tion that does not
produce any harmonics, this pre-equalization process can be
compensated when the record is played by applying an inver
-
ted equalization curve to the actual pressing curve.
Before the so-called RIAA equalization became standard in
the mid 1950s, recording studios often used different fre
-
quency response curves when cutting their records. When
such records are played back via an RIAA equalizer, the sound
quality suffers. The PH 8.3 therefore offers a selection of the
six most common equalization curves using the EQ selection
keys (4). Often the labels or record sleeves of older records
show the pre-equalization used at the time. This can be used
to set the correct equalization curve on the PH 8.3.
