the critical current-to-voltage conversion
stage with dedicated operational amplifiers
possessing superlative rise time and band-
width characteristics. Each channel incorpo-
rates two of these DACs in a dual-mono
mode configuration. Following this, a custom
active filter circuit sums both halves of the
balanced signal and provides excellent com-
mon mode noise rejection in addition to its
outstanding audio characteristics. This
approach to the digital-to-analog circuit topol-
ogy yields extraordinarily low distortion,
improved signal-to-noise ratio and superb,
musical sound quality.
Following the active filters, the signal passes
through the volume control. The Nº51 vol-
ume control is built around a dual MDAC 12-
bit ladder attenuator, derived from the Nº40.
Volume controls are a critical part of any
audio product, and multi-channel audio is
particularly demanding. Offsets in volume
level between channels can be large, yet
always need to be maintained in a precise
relationship over the entire control range.
The Nº51 volume control uses a hybrid ana-
log/digital attenuation scheme to achieve a
remarkable 100dB control range at 0.1dB res-
olution for the entire range. By applying DSP
based digital attenuation only to fill in the
gaps for the very lowest level volume control
steps, we do not suffer the loss of resolution
associated with pure digital volume controls.
For music reproduction, the Nº51 offers sep-
arate, fully balanced front left and right out-
puts in addition to a 5.1-channel output.
Additional attention was given to these chan-
nels resulting in a design which maintains
fully balanced signals from the digital-to-ana-
log conversion stage to the output.
Conclusion
The Nº51 represents the next step in the evo-
lution of the Mark Levinson product line. It
combines superb video and audio perform-
ance while remaining true to the core princi-
ples of Mark Levinson. It is designed to ele-
vate the enjoyment of DVD-Videos and CDs
to a remarkably high level. New features,
such as HDMI, allow the stunning video
quality of the Nº51 to be appreciated, while
the tried and true analog audio circuitry
make it a remarkably musical product. The
Nº51 Media Player owner can take pride in
knowing that they have purchased the finest
instrument available for the enjoyment of
their film and music collections.
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