Madrigal Imaging N380 Stereo Amplifier User Manual


 
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the SSP must not
be in a tape loop
The last remaining alternative would seem to be to insert the decoder “within” a
preamplifier by hooking it up in a tape loop. Unfortunately, this setup returns the
Left and Right outputs of the decoder to the preamplifier, where they can be in-
appropriately changed without changing the Center and Surround outputs. It is
therefore inappropriate to place surround sound decoders in a tape
loop.
It would seem that there is no way to properly integrate a surround sound pro-
cessor with a preamplifier for a high quality, dual-purpose system.
the SSP & the Nº380 The Nº380 solves this dilemma by virtue of a specially-designed surround sound
processor interface. When you select the ssp name for a particular input on the
Nº380, the output level and balance controls are defeated and the preamplifier
operates in a “unity gain” mode, passing through whatever signal enters that input
without changing its volume in any way. In fact, the display indicates that a line-
level signal is being “passed through” unchanged by showing “LINE” in the display.
Thanks to this design innovation, it is possible for the first time to correctly
integrate a surround sound processor with a preamplifier, sending the
processor’s Left and Right outputs through the Nº380 (and on to the power am-
plifier for the main front speakers). Since the output level of these channels can-
not be changed by the Nº380 while in “ssp” mode, the preamplifier cannot cor-
rupt the careful calibration of the processor’s output levels. And since the audio
portion of audio/video sources are fed directly to the processor’s audio input(s)
at a line level, input calibration cannot be disturbed by the preamplifier.
Note: the Nº380 will not allow an input with an “ssp” name to be
selected during initialization, since allowing a line level signal
to pass through unattenuated at start-up presents a potential
hazard to your loudspeakers.