Simaudio 610LP Phono Preamplifier User Manual
Page 11
610LP Dual-Mono Phono Preamplifier
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11
Gain Setting:
There are sixteen (16) unique gain level settings
available using DIP switches 2 through 5, located at
the top of the lower DIP switch bank. The range of
available settings runs from 40dB all the way up to
70.0dB:
Figure 4: Left and right channel DIP switches for gain level settings
The factory default gain level setting is 40dB
whereby DIP switches 5, 4, 3 & 2 are set to the right
position (’OFF’). This setting would be
applicable for most moving magnet
cartridges.
The example to the right shows a gain level setting
of 60.0dB where DIP switches 5 and 3 are in the left
(‘ON’) position and DIP switches 2 and 4
are in the right (‘OFF’) position.
When you are using a moving coil cartridge, you will
need to increase the gain level setting. This is a
general rule for determining the gain of a MC
cartridge: For a low output MC cartridge (0.7mV and
lower), set the gain level to at least 66dB; for a
medium output MC (0.7mV to 1.5mV) set the gain
level to 60dB; for a high output MC (> 1.5mV) set
the gain level to 54dB. Since every audio system is
different, these are just approximated values.
Equalization Curve:
The MOON 610LP Phono Preamplifier is
equipped with circuitry for two (2) different
equalization curves; The RIAA standard and the less
common IEC modified curve. The main difference is
that the RIAA curve produces a flat frequency
response from 20Hz to 20kHz; The IEC curve acts as
a subsonic filter removing inaudible infrasonic bass
only
below 20Hz. Using DIP switch 1 on lower bank.
The factory default is the RIAA curve whereby DIP
switch 1 is in the right (‘OFF’) position. To change to
the IEC curve, simply move this DIP switch to the
left (‘ON’) position.
Figure 5: Left and right channel DIP switches for equalization curves
To determine which curve is best for you, perform
this simple test: Use the 610LP with the RIAA curve
and watch the movement of your loudspeaker’s bass
drivers. If their motion doesn’t follow the pattern of
the record you’re playing or you see excessive driver
movement, chances are you should use the IEC
curve to eliminate the subsonic information not
present on the record.