Madrigal Imaging N380 - Manual (Page 22)

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results of unrealistic tests The Nº380 Preamplifier has been optimized to yield optimum sonic performance
under normal, real-world operating conditions. This approach involves no disad-
vantage when the unit is used as designed.
Unrealistic tests such as listening at full gain to an unterminated input which has
been associated with an unterminated record output may result in some small
amount of noise at the main output which does not occur when the Nº380 is
used correctly. Moreover, even under these unrealistic test conditions, any result-
ing noise is small and poses no danger.
Rather than compromise the sonic performance of the preamplifier in an effort to
eliminate even the remote possibility of this noise being detected, the setup pro-
cedure outlined above for programming input names was designed to make it
virtually impossible to create a condition under which any such noise can be
heard. We recommend using the input name
NOT USED for all unused inputs.
programming input offsets The Nº380 allows you to adjust the relative outputs of your various sources with
respect to one another, so as to avoid disturbing and/or potentially dangerous
changes in output levels as you switch from one source to the next. These
input
offsets are made relative to whichever source tends to be the loudest—that is,
you raise the outputs of the remaining sources to match that of your loudest
source. This is achieved as follows:
1 DECIDE WHICH SOURCE HAS THE HIGHEST OUTPUT
You should listen to several examples of each source before you decide
(e.g., to several different CDs when evaluating your CD player’s output, or to
several radio stations when evaluating your tuner’s output). The point is to
ascertain whether any source consistently plays more loudly than others,
and to bring the others up to its level. (For example, other things being
equal, balanced outputs of components are usually approximately 6 dB
stronger than the single-ended outputs.)
2 LISTEN TO THIS SOURCE LONG ENOUGH TO ESTABLISH ITS VOLUME
Use a particular output level setting to which you can easily return, such as
60.0 in the display. Develop a sense of the perceived volume at this setting,
which you will want to match with your other inputs. Optionally, you may
desire to measure its actual output at your chosen volume setting with a
sound pressure level (SPL) meter set to “Slow” or “Average” response.
3 SELECT THE FIRST OF THE SOURCES WHOSE OUTPUT YOU WILL RAISE
While music is playing from both your reference, “loudest” source and the
source you are about to adjust, select the latter so as to give you a sense of
the magnitude of the adjustment you are about to make.