M15 HD AV Surround Sound Preamplifier
Premium parts from renowned suppliers like Burr-Brown and Texas Instruments,
are used in classic NAD circuit configurations to provide the low distortion and
sonic realism for which NAD is famous. With full 24-bit 192kHz analogue-to-
digital and digital-to-analogue conversion, the M15 HD can fully exploit the
best source material available today and for the foreseeable future. Unusually,
the M15 HD uses multiple 2-channel DACs rather than the 8-channel DACs
favoured by many of today’s surround sound processors. We have found that
the sonic performance of the 2-channel DACs used in a dual differential mode
is well worth the extra cost of this configuration.
Unprocessed analogue inputs, whether stereo or via the 7.1 input, remain in
the analogue mode, sometimes known as ‘bypass’ mode. If a digital processing
mode is selected, these signals are digitized using a 128x over-sampling Sigma/
Delta ADC that employs a linear phase digital anti-aliasing filter to prevent any
trace of ripple in the audio band.
Super high-speed (8 MHz bandwidth) low distortion (0.00008% THD) amplifiers
are used for analogue input and output buffers. These FET OPAmps feature
high slew rate and are capable of the high output current required by this
application. Low noise and superb dynamics are assured.
VIDEO PERFORMANCE FEATURES
The M15 HD features NAD’s newly developed HDMI repeater featuring Sigma’s
VXP Image Processor. Both analogue and digital video sources can be selectively
processed using Sigma’s advanced VXP algorithms. This is the best performing
image processing engine we could find, using custom algorithms developed for
the broadcasting industry. These algorithms are embedded in one of the most
advanced high speed DSPs on the market which results in class leading processing
latency of less than 1/50th of a second, or about one frame of video!
The new VXP video board features video conversion to resolutions as high as
1080p and supports all SD and HD formats up to 2048 x 2048 pixels. Motion
adaptive de-interlacing with edge interpolation eliminates the jagged edge
effects common in lesser image processors. Film mode detection with output
cadence generation endows the video picture with a film-like smoothness of
motion. The programmable scaling engine also allows for aspect ratio conversion
to perfectly match the video source with the video display. Advanced noise
reduction and detail enhancement improve legacy analogue video sources to
near HD quality.
All SD analogue sources can be processed to HD output via analogue
Component Video or Digital HDMI. This allows true ‘one cable’ convenience
by converting all the different input source components to one HD video
format to send to your TV display or projector. OSD is also available on all
video formats.
DIGITAL PERFORMANCE, PERFECTED
The M15 HD is a clean sheet design, evolved over several years of intense
development. New thinking about D/A and A/D conversion processes led to a
circuit design that offers a level of technical precision and sonic performance
unprecedented at this price level.
The M15 HD also supports Audyssey MultEQ Pro, an exciting new room
correction technology that uses actual measurements of your room to create
precision digital filters to correct for the effects of room boundaries. Unlike
tone controls or even multi-band equalizers, Audyssey can correct for time
(phase) as well as frequency errors. And unlike previous digital room correction
technologies that sounded great in the sweet spot but worse outside the sweet
spot, the Audyssey system creates a wide, ‘family–sized’ sweet spot where the
sound is uniformly excellent for all listeners. Audyssey MultEQ Pro must be
professionally calibrated by a specially trained professional sound engineer. The
result of this calibration is a complex digital filter that is stored in the M15 HD’s
memory and is applied to all audio signals.
