Mark Levinson 53 - Manual (Page 7)

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Nº53 Power Amplifier
to maintain separation while minimizing critical current loop areas.
The top compartment contains the control circuitry, also with its
own independent regulated supplies and shielding from the heart
of the amplifier. Special attention was made to critical signals that
need to pass between different boards. Extensive use of low-
voltage-differential signaling (LVDS) for control signals is used to
maximize signal integrity while all critical analog signals remain
balanced to offer superb noise rejection.
The four interleaved amplifier modules are the crux of the superior
performance offered by the Nº53 - a larger dynamic range, cleaner
operation, and higher power levels. Our proprietary Interleaved
Power Technology (IPT), developed and perfected through years of
extensive listening tests and measurements, is based on the
rudiments of digital switching while avoiding the common
problems of most switching amplifiers.
“Dead bands” and output device limitations are common problems
in typical switching amplifiers, which use different output devices
for the positive and negative parts of the audio signal. Since both
devices cannot be active at once without overloading their power
capability, dead bands are caused by the lack of signal during the
transition between the devices. Adding to the audible distortion
resulting from these dead bands is the signal degradation caused by
device limitations, such as output power and switching frequency.
To compensate for these deficiencies, an aggressive filter is placed at
the audio output to eliminate introduced switching noise but this
in turn degrades the audio signal. The end result is an amplifier with
very poor sound reproduction ability.
The Nº53 supports the activation of both switching devices
concurrently, totally eliminating the problem of dead bands while
reducing stress on the output devices, permitting much higher
voltage rails and output power. Our proprietary IPT technology
features the use of four separate amplifiers, each of which digitally
manages a portion of the audio signal. The outputs of the amplifiers
are then recombined for the final output stage. This approach
provides the Nº53 with a very high switching frequency, enabling a
much smoother, cleaner roll-off by moving the noisier switching
frequencies further out of the audible range – and since the
frequency response extends well beyond the audio band, the output
filter is much less aggressive, minimizing audio signal degradation.
With phenomenal output power capability, a larger dynamic range,
cleaner operation, higher switching frequency, and a much lower
noise floor than even most traditional linear amplifiers, the Nº53
provides extraordinary audio performance and proves once again
that Mark Levinson power amplifiers truly represent the finest
audio amplifiers available.